Considering their domestic struggles, winning the Europa League is Arsenal's only realistic hope of playing Champions League football next season. Instead, it turned out to be one of the worst performances from Mikel Arteta's lacklustre team. Arteta's tactic of playing a false nine in such a crucial game failed, but Arsenal players also produced an underwhelming outing at Villarreal.
Unai Emery's Villarreal were simply better and more prepared for the game. They netted twice within the opening 30 minutes, and on both occasions, Arsenal were undone by their poor defending.
Dani Ceballos' sending off made the 10-man Gunners more eager to find a breakthrough. As the match wore on, the Yellow Submarines began to show signs of fatigue. That allowed Arsenal a chance of securing a comeback.
Fortunately, Villarreal managed to hang on to heir 2-1 lead at home and now head into the second leg, confident of advancing to the final.
On that note, let's have a look at the ratings of players from both teams in the game.
Villarreal Player Ratings against Arsenal
Geronimo Rulli: 6/10
Geronimo Rulli had very little to do all game, as Arsenal struggled to muster any shots on target. Although the 28-year-old Argentine was unable to stop Pepe from scoring his penalty, Rulli did well to deny Pierre-Emerick Aubameyang's effort late in injury time.
Juan Foyth: 6/10
It was a great performance from Juan Foyth, who impressed with his blistering pace and eagerness to bring the ball forward. However, the Villarreal defender pulled his hamstring in the second half and was forced off.
Raul Albiol: 7/10
Coming from the back of the post, Raul Albiol was amongst the unmarked Villarreal players in Arsenal's penalty box as he netted the Yellow Submarines' second goal of the night, helping his team secure victory at home.
Pau Torres: 7/10
Pau Torres excelled at the back and did well to stop Arsenal from entering his team's penalty area.
Alfonso Pedraza: 7/10
The Spanish left-back was largely untroubled at the back. Alfonso Pedraza also showed plenty of enthusiasm in moving the ball forward into Arsenal's half.
Samuel Chukwueze: 8/10
In an impressive outing, Samuel Chukwueze, who has scored three goals in his last three La Liga matches, created all sorts of trouble for Granit Xhaka and the Arsenal defence.
Etienne Capoue: 5/10
Etienne Capoue received two yellow cards in the second half and had to leave the field on a stretcher after clattering onto Bukayo Saka. While it is hoped that his injury is not too serious, the former Tottenham Hotspur player will likely miss the return leg at the Emirates Stadium.
Dani Parejo: 6/10
Dani Parejo had some excellent touches throughout the game. He swung in a great ball for Villarreal's second goal and also played a role in getting Dani Ceballos sent off after the Arsenal midfielder stepped on his foot.
Manu Trigueros: 6/10
The Villarreal midfielder managed to dash into Arsenal's penalty box unmarked. His well-taken goal gave Villarreal the lead in the game. However, in the second half, Manu Trigueros gave away a penalty that allowed Arsenal to score an away goal.
Gerard Moreno: 6/10
Before Arsenal pulled one back, Gerard Moreno had the chance to extend Villarreal's lead. Unfortunately, his shot was saved by Bernd Leno. Nevertheless, Moreno was a goalscoring threat throughout the match and could remain one in the return leg at Arsenal too.
Paco Alcacer: 6/10
The 27-year-old started the game with six goals in seven Europa League fixtures for Villarreal. Although Paco Alcacer didn't get onto the scoresheet, his teammates did enough to get a two-goal lead over Arsenal. The striker was replaced after the break in favour of Francis Coquelin.
Ratings of Villarreal substitutes against Arsenal
Francis Coquelin: 6/10
The former Arsenal player played well after coming on at the start of the second half. There were a couple of chances for Francis Coquelin to break forward, and he did just that to support his team.
Mario Gaspar: 5/10
Mario Gaspar replaced Foyth, who came off with a hamstring injury but had difficulty performing as well as his predecessor. Gaspar looked a little uncertain at the back, and Arsenal could capitalise on that in the second leg.
Alberto Moreno: 5/10
Returning from his long-term cruciate ligament injury, Alberto Moreno was not at his best. He allowed Arsenal players to get past him on a couple of occasions.
Moi Gomez: 5/10
There was not much Moi Gomez could do after he came on in the 79th minute, as Arsenal were dominating the game and pushing Villarreal back into their own half.
Ratings of Arsenal against Villarreal
Bernd Leno: 5.5/10
Unlike in the match against Everton, Arsenal custodian Bernd Leno could do very little about the two goals he conceded against Villarreal. Overall, he did well to deny Villarreal from extending their lead.
Calum Chambers: 5/10
Calum Chambers had plenty of time on the ball but failed to contribute much to Arsenal's attack. His link-up play with Saka was not good enough as well. However, the English international deserves some credit for his good work in the Arsenal defence.
Rob Holding: 5/10
Defensively, Rob Holding did not make too many mistakes. However, he squandered a couple of chances to score at the other end of the field.
Pablo Mari: 4/10
Pablo Mari was too slow for Villarreal's quick attackers on the night. He was often caught out of position and may not start the return fixture next week.
Granit Xhaka: 5/10
The Swiss international could not quite cope with the constant pressure from Chukwueze, as he was beaten far too often by the Nigerian. With Kieran Tierney expected to be fit soon, Granit Xhaka could return to the Arsenal midfield for the next game.
Thomas Partey: 5/10
Without his regular midfield partner Xhaka, Thomas Partey struggled to be as effective as Mikel Arteta would have wanted him to be.
Partey's shots on goal flew wide on the night. The defensive midfielder was also partly at fault for Villarreal's first goal, as he failed to clear the ball in time.
Dani Ceballos: 2/10
Dani Ceballos was totally overrun by Villarreal and hardly exerted any influence on the game. On his return to Spain, the Real Madrid loanee was duly awarded a second yellow in the second half and left the pitch.
It was an absolutely abysmal performance from Ceballos, who has now become a liability for Arsenal.
Bukayo Saka: 5.5/10
While Bukayo Saka was close to silent in the first half, he sprung into action when required and won a penalty for Arsenal. It was certainly not his best game, but the youngster's contribution aided Arsenal's efforts in getting onto the scoresheet.
Emile Smith Rowe: 5/10
Aside from the opening few minutes, Emile Smith Rowe had very few moments on the ball after being played out of position. He lost possession four times in the first 45 minutes, had just 16 touches and created zero chances for Arsenal.
In the second half, Smith Rowe became more involved in the game and made some crucial interceptions at the back too.
Martin Odegaard: 4/10
Like Ceballos, Martin Odegaard endured a poor night in Spain. The midfielder created very few chances for Arsenal and gradually became anonymous as the game wore on.
Nicolas Pepe: 6/10
Leading the line in Arsenal's attack, Nicolas Pepe earned a penalty in the first 45 minutes. But that was overturned by the video assistant referee for a handball in the build-up. After Saka won another penalty for Arsenal, the Ivory Coast international made no mistake from the spot as he netted a crucial away goal.
Ratings of Arsenal substitutes against Villarreal
Gabriel Martinelli: 5/10
Gabriel Martinelli had a quiet game, but his presence helped Arsenal venture forward and attempt to penetrate Villarreal's defence more frequently.
Pierre-Emerick Aubameyang: N/A
Returning from his illness, Arsenal captain Pierre-Emerick Aubameyang replaced Bukayo Saka in the 85th minute of the match. Aubameyang nearly made it 2-2 for Arsenal, but his effort was blocked by the Villarreal goalkeeper.
Willian came on in the last few minutes of the game to swing in a corner, but that was ultimately headed wide.
Mohammed Elneny: N/A
Mohamed Elneny came on too late to make an impact on the game as Villarreal hung on.