Arsenal shot themselves in the foot last night after they conceded a potentially devastating late goal at the end of a match they should and could have won at a stroll against 10-man Madrid.
It was symptomatic of Arsenal in Europe over the years as they out-played a supposedly superior side only to concede when it seemed they had nothing to worry about.
Alex Lacazette had given Arsenal a deserved second half lead against a Madrid side which had a player sent off after nine minutes and manager Diego Simeone dismissed soon after.
But Antoine Griezmann’s late equaliser, a poor one from Arsenal’s point of view, means the Spanish side will be red hot favourites to go through to the final when they play the second leg in Madrid next Thursday.
What a disappointing way for manager Arsene Wenger to play out his last European home tie after over two decades at the helm.
And it looked like it would be a celebration of all the good things the French manager stood for.
A stirring pre-match build-up with a stadium bedecked with red and silver flags and blaring music, Arsenal started pumped up and with intent.
Madrid, showing their characteristic ruthless defensive approach, picked up a yellow card from French referee Clement Turpin inside the opening two minutes when he cautioned Sime Vrsaljko for hacking down Jack Wilshere in full flow.
Arsenal were relentless in their attack and Alex Lacazette went close with a volley which clipped a post from a Welbeck cross.
Slovenian keeper Jan Oblak then showed why he is rated one of the best in the world today with a brilliant one-handed save from Lacazette’s header.
Then with barely ten minutes gone Croatian right-back Vrsaljko was sent off for his second bookable offence – this time treading on Lacazette’s ankle.
Simeone, as ever, was doing his nut on the touchline and then had to join his player in shame for running on the pitch trying to get Hector Bellerin booked for an innocuous challenge.
The French official was firm but fair and and his fellow countryman, Wenger, sensibly stayed in his seat in the dug-out sending out a message of calm and serenity to his men.
And they needed to remain patient as Madrid’s well-drilled ten men formed a belligerent defensive shield.
There were chances for Arsenal, though, most notably for Danny Welbeck, who shot too close to Oblak when only six yards out.
David Ospina, in the Arsenal goal ahead of Petr Cech, was having to run around just to keep warm.
But as much as Madrid were flapping, fouling and cheating where possible, there was a growing sense that Arsenal would pay the price if they did not take advantage of their total dominance.
The warning signs were never more apparent than when Griezmann produced two saves in quick succession from Ospina, the second a great stop from the Colombian.
If there is one team in modern football playing against ten men is almost a disadvantage it is this Simeone side.
And the start of the second half seem to bear that out as Arsenal struggled to create chances as they seemed to run out of energy and ideas in equal measure.
But Wenger had warned the world not to underestimate the resilience and self—belief of his embattled squad and with about half an hour to go, Lacazette leapt to an obscene height for someone of his stature to head in from an inch-perfect Wilshere cross.
It was just about the first meaningful contribution form the enigmatic England midfielder, but what a telling one.
And the finish from Lacazette, who could have been a Madrid player had they not been under a transfer ban last summer, finished with the ruthlessness that means he has now scored 53 goals since the start of last season, the most of any Frenchman in the top five European Leagues.
That includes, of course, Griezmann, who was now playing as a lone forward looking for the odd scrap on the break.
But he was starved of the ball as Arsenal again attacked in numbers with Lacazette, Ramsey and Welbeck all getting into dangerous goalscoring positions.
The atmosphere was electric, the stadium full and the noise unprecedented at this relatively new stadium.
Wenger, sitting cool in his dug-out still, must have been wondering why his players had waited for him to get the elbow before playing with such conviction.
Simeone, relaying instructions from the Arsenal directors’ box, made changes to try and shut up shop and keep the score down to just the one goal deficit.
It was a smart move knowing how good Madrid are at home, with only two defeats all season and 11 consecutive clean sheets in recent weeks.
Then came the hammer blow that could most likely settle this tie as Griezmann scored in the 82nd minute.
The French forward shrugged his fellow French international Laurent Koscielny off the ball and then followed up the rebound of his own shot to lift the ball into the net above a slipping Shkodran Mustafi.
Too easy and an oh so familiar few sloppy seconds from the Arsenal players who looked, like their supporters, broken at the final whistle.
Ospina 7, Bellerin 7, Mustafi 5, Koscielny 4, Monreal 6, Xhaka 7, Ramsey 6, Wilshere 6, Ozil 6, Welbeck 4, Lacazette 8. Subs: Cech, Holding, Iwobi, Chambers, Maitland-Niles, Kolasinac, Nketiah.
Oblak 8, Vrsaljko 0, Gimenez 6, Godin 7, Lucas 6, Correa 5 (Savic 75, 6), Thomas 6, Saul 6, Koke 6, Griezmann 7 (Torres 85), Gameiro 5 (Gabi 65, 6). Subs: Werner, Savic, Diego Costa, Machín Pérez, Olabe.
Clément Turpin (FRA) 8