The Europa League semi-finalists lit the touch paper on Thursday night after two enthralling games between Manchester United and Roma and Villarreal and Arsenal.

Both games dished up eleven goals combined, with the Red Devils blowing away the Serie A side and looking nailed on to reach the final after a brilliant attacking display in the second half saw them romp to a 6-2 advantage.  

There were some top performances at Old Trafford, including from veteran forward Edison Cavani, but also some displays to forget on the opposing side as Chris Smalling and Henrikh Mhkitaryan failed to impress on their return to the club.

Over in Spain, it was Unai Emery who was walking away smiling as he got one over his former club and successor Mikel Arteta – securing a 2-1 first leg advantage, the perfect way to silence his Gunners critics after being sacked in 2019. 

Sportsmail looks back on both semi-final games, analysing six things we took in from two action-packed contests.

The Europa League semi-finals gave us two exciting games as United romped to a 6-2 win

Arsenal have work to do after losing 2-1 against former boss Unai Emery's Villarreal side

Arsenal have work to do after losing 2-1 against former boss Unai Emery’s Villarreal side

Mikel Arteta’s tactical gamble fails to pay off

For the Arsenal board, Thursday night’s result was the worst case scenario – the man they sacked outmanouevering the man they replaced him with.

Unai Emery’s Arsenal career ended with a whimper as he was axed 18 months into his stint at the Emirates, but Arteta was supposed to offer a fresh new start for a club sorely lacking a true identity.

But Emery showed he is still the king of the Europa League as he used the weaknesses he is well aware Arsenal still possess to his advantage. Meanwhile, Arteta’s ploy at playing without a striker backfired spectacularly.

Mikel Arteta was outdone by Arsenal predecessor Unai Emery as Villarreal beat his side 2-1

Mikel Arteta was outdone by Arsenal predecessor Unai Emery as Villarreal beat his side 2-1

His decision to deploy Emile Smith-Rowe as a false 9 backfired with Gunners lacking sparkle

His decision to deploy Emile Smith-Rowe as a false 9 backfired with Gunners lacking sparkle

The former Manchester City assistant boss took a leaf out of Pep Guardiola’s book by fielding Emile Smith-Rowe as the false 9, but it left the team lacking sparkle in the first half. Arteta was forced to swallow his pride and bring on Pierre-Emerick Aubameyang and Gabriel Martinelli later on when he realised his tactics had failed.

But the changes came far too late in the day as Aubameyang entered the fray in the final five minutes while Willian was introduced in stoppage time. Martinelli was given a 30-minute run out but Arteta showed a stubbornness by refusing to rip up his game plan Villarreal were seeing it out.

Fans will be happy to see back of ‘out of his depth’ Ceballos

Dani Ceballos has had mixed reviews during his two-year loan spell in north London, but his first years at the club left supporters craving an extension on the agreement from Real Madrid. 

But his second campaign has been underwhelming to say the least, and after he became the villain on Thursday night after getting himself sent off following two bookings, Gunners fans may not be too bothered if he heads back to the Bernabeu.

Dani Ceballos' red card could seal a return back to Real Madrid after a mixed bag of a season

Dani Ceballos’ red card could seal a return back to Real Madrid after a mixed bag of a season

Usually we’re used to seeing his midfield partner Granit Xhaka press the self-destruct button, but this time it was Ceballos’ turn for a reckless display. He picked up his first yellow just before half time, and was given his marching orders after leaving a foot on Dani Parejo.

He had hardly impressed before being sent for an early bath on 57 minutes, and was slammed by club legend Martin Keown, who said the Spaniard was ‘out of his depth’ on the night.

‘Dani Ceballos has made a catalogue of mistakes in the Europa League. He looked out of his depth tonight. There was a huge hole in midfield which Emery exploited.’ 

The player himself has already written off any chances of an extension to his deal at the Emirates – admitting he likes LaLiga ‘a lot more’ than the Premier League ahead of the game at Villarreal.

The Spaniard was labelled 'out of his depth' by Martin Keown as he left the Gunners in the lurch

The Spaniard was labelled ‘out of his depth’ by Martin Keown as he left the Gunners in the lurch

He conceded he had endured ‘a bad time’ this term and was lacking the consistency of his first year and said another loan would be ‘difficult’. 

‘I’ve had a bad time because I didn’t have the consistency I had last year,’ Ceballos told Onda Cero ahead of Arsenal’s Europa League semi-final tie against Villarreal on Thursday. ‘These last five or six games I’ve played at a good level.

‘To be honest I like LaLiga a lot more. The Premier League is more complete but with my style, La Liga is much better for me.

‘Another loan would be difficult from both sides, for Real Madrid and for me.’

Gunners desperately lacking leadership

Ceballos’ red card summed up Arsenal’s glaring problem in recent years – an inability to control games and keep discipline, with no organisation or a leadership figure to keep the team in check. 

Their current club captain is Pierre-Emerick Aubameyang, a player who can’t even get into the team at present and who was recently disciplined for turning up late to travel with the squad. 

Where are the rest of the leaders? Granit Xhaka took the armband on the night but we know his own history of mishaps and ill discipline – once swearing at his own supporters and having the captaincy stripped away from him. 

Arsenal showed a lack of control and organisation, summed summed up by the Ceballos red

Arsenal showed a lack of control and organisation, summed summed up by the Ceballos red

Mikel Arteta slammed his side for being 'disorganised', a problem Arsenal have had for years

Mikel Arteta slammed his side for being ‘disorganised’, a problem Arsenal have had for years

After Ceballos’ red card, Mikel Areteta’s side have now suffered 10 dismissals since he took over from Emery – twice as many as any other side in the same period. There is a focus missing from the squad. 

This is a problem Arsenal have had since Arsene Wenger was in charge – the lack of an influential figure who can push the team on. Even though youngsters like Smith-Rowe and Bukayo Saka have impressed, there is too much inexperience in the current side.

Arteta himself admitted his side were ‘disorganised’ in Spain and lacked control.

‘In the first half, there were so many moments that we weren’t us,’ he said after the game. ‘We weren’t clear with our high press, we were disorganised, we were not precise with the ball and we didn’t have enough control.   

Bruno banishes burnout fears

Fernandes has been one of the shining lights for Manchester United this season – but in recent games his form has tailed off, leading to concerns he may be burnt out having played a whopping 52 games in all competitions.

He had failed to grab a goal or assist in any of his previous four games, and – such is the standard he has set for himself – Sportsmail yesterday pondered whether he might be suffering from exhaustion after missing only two games in the whole campaign. 

And in his last 14 games, he had only netted twice in a sensational season that has seen him become United’s top scorer with 26 goals. 

Bruno Fernandes allayed fears he could be burnt out with a virtuso display against Roma

Bruno Fernandes allayed fears he could be burnt out with a virtuso display against Roma 

The Portugal star netted twice and also provided two assists to put United in control of the tie

The Portugal star netted twice and also provided two assists to put United in control of the tie

But the Portugal playmaker brushed those fears aside with a commanding display in the heart of Ole Gunnar Solskjaer’s midfield against Roma – acting as the central outlet with two goals and two assists in their 6-2 thrashing. 

He got the ball rolling for United by netting the opener to finish off a superb passing move involving Pogba and Cavani – who slipped the midfielder in to prod home from an angle. 

Fernandes then turned provider for the Uruguayan as he drove forwards with the ball before playing an inch perfect pass to the forward, who slammed into the corner to put them level.

Fernandes has missed just two games all season but clearly still has more fuel in the tank

Fernandes has missed just two games all season but clearly still has more fuel in the tank

He played a big role in getting them back in front as he slid a pass across to Pogba, whose effort was rebounded into the path of Cavani for his second. 

He got a double of his own when he confidently dispatched a spot kick after the veteran striker was felled in the area by Chris Smalling, and his beautiful dinked ball was put on a plate for Paul Pogba to add a fifth. 

Fernandes was back to his best – and just in time for the big occasion. Did the 26-year-old read our piece doubting his fitness before taking to the field at Old Trafford? He was sensational.

Should United avoid a disaster and reach the final then they will be clear favourites when their talisman is in this kind of form. 

Greenwood loves to end the season with a flourish 

Another United player who caught the eye was young Greenwood, who is carving out something of a repuation as a player who goes out with a bang. 

This time last year we were raving about the teenager after his goal gut towards the end of the 2019-20 campaign broke a string of records at United as he scored five in his last seven, and he’s showing the same scintillating form this time around after a relatively quiet start.

This has been a tough campaign for Greenwood – who was banished from the England squad after being involved in a controversial incident alongside Phil Foden where they invited girls back to their team hotel before facing Iceland in September. 

Mason Greenwood is finishing the campaign strongly for the second year running after scoring yet another goal in the 6-2 win over Roma

Mason Greenwood is finishing the campaign strongly for the second year running after scoring yet another goal in the 6-2 win over Roma

He has followed on from his goal gut last year with the teenager netting six in his last eight

He has followed on from his goal gut last year with the teenager netting six in his last eight 

The media storm around that will have had a huge impact on him mentally – he only netted once in the Premier League before he started picking up form again in March – but he’s now bettered his tally from the end of last season by netting six in his last eight games.

And his strike against Roma – which put the cherry on the cake with a sixth of the night – means he has scored 27 goals for the club in all competitions while still only at the age of 19. That’s the third highest of any player in United’s history after Goerge best (37) and Norman Whiteside (39). 

His sparkling recent displays will give him a huge boost of making Gareth Southgate’s England squad for the Euros this summer. 

Smalling fluffs chance for Old Trafford redemption

One player who did not impress was arguably the man with the biggest point to prove – Chris Smalling. 

The former Red Devils defender was outcasted by Solskjaer during his time at Old Trafford and shipped out on loan to Roma, where he redeemed himself with some solid displays at the back and earning himself a permanent move.

The 31-year-old has since emerged as a first choice defender under Paulo Fonseca, and he was given a golden opportunity to show United they were wrong to part ways with him back in 2019 by frustrating them in Manchester, but did anything but.

Chris Smalling failed to seize a chance to impress back at United after an error-strewn display

Chris Smalling failed to seize a chance to impress back at United after an error-strewn display

The 31-year-old was at fault for a number of Roma's six goals and looked all over the place

The 31-year-old was at fault for a number of Roma’s six goals and looked all over the place 

Smalling was all over the place in the semi-final, and was largely at fault for a majority of the six goals they let in. For United’s second goal, he left Edinson Cavani completely unmarked as he was dragged out of position following a quick one-two, allowing the Uruguayan to sweep home an equaliser to make it 2-2.

He then clumsily fouled the veteran to give away a penalty, which Fernandes slotted away to add a fourth and was easily out-jumped by Paul Pogba who was able to head in number five from Fernandes’ cross.

His second year in Rome has not been as successful as his first, and injury problems have seen him miss a huge chunk of the campaign. But he had a real chance to make a statement here – alongside another former United star in Henrikh Mhikitaryan – and neither took it.

Coming back in the second leg looks nigh-on impossible, but Smalling still has a chance to redeem himself with a much improved defensive effort when United travel to Roma.