Julian Alvarez's penalty secured Atletico Madrid a 1-1 draw against Arsenal in a nervy Champions League semifinal first leg clash on Wednesday.
Viktor Gyokeres sent the Premier League leaders ahead from the spot just before the interval after he was fouled, but Alvarez followed suit 10 minutes into the second half after Ben White's handball.
Arsenal were upset at a late penalty decision being overturned following a VAR review when David Hancko made contact with Eberechi Eze in the area.
Atletico had the better for long periods but Arsenal's solid defending helped them leave the Spanish capital in a good position to return to the Champions League final 20 years after their last appearance.
What the game lacked in the dizzying goal rush of Paris Saint-Germain's 5-4 win over Bayern Munich in the other semifinal the night before, it replaced with tension and a desperation not to fall behind.
Toilet paper rained down from the stands of the Metropolitano stadium minutes before kick-off, in a striking – if wasteful – display, which invited cynical jokes from some quarters about the calibre of the spectacle ahead.
In a tussle between arguably the continent's two biggest teams never to lay a finger on the trophy neither wanted to blink first.
Atletico still have an outdated defensive reputation but pinned Mikel Arteta's miserly Arsenal back in the early stages, with David Raya tipping Alvarez's shot around the post.
The Gunners, a long way from Arteta's eve-of-the-game demand they dominate proceedings, looked to smash and grab, with Marc Pubill blocking from Martin Odegaard on a quick breakaway.
Noni Madueke, starting on Arsenal's right flank with Bukayo Saka only fit for the bench, hammered just wide from distance as last year's beaten semifinalists sporadically emerged from their half.
The next time they did, Gyokeres won a penalty. The Swedish striker, who might not have started if Kai Havertz was fit, exchanged passes with Martin Zubimendi and Hancko clumsily shoved him in the back from behind.
Diego Simeone and Atletico veteran Antoine Griezmann begged for the decision to be reviewed but VAR saw no reason to intervene.
Gyokeres took the spot-kick himself, walloping it past Jan Oblak, who dived the right way but stood no chance of keeping it out.
ATLETICO BATTLE BACK
Three-time runners-up Atletico, back in the semifinals for the first time in nine years, came out guns blazing in the second half.
Raya saved Ademola Lookman's drive with Gabriel blocking Griezmann's follow-up.
The hosts pulled level from the penalty spot after White handled Marcos Llorente's shot, the ball bouncing up and hitting his arm, which was away from his body.
Alvarez took it, and having missed in Atletico's Copa del Rey final shoot-out defeat earlier in April, this time made no mistake with an unforgiving blast rivalling Gyokeres's first-half effort.
MLS-bound Griezmann looped a shot off the crossbar and then sent the rebound off target as Atletico turned the screw in pursuit of an advantage to take into next Tuesday's second leg.
Nigeria international Lookman twice came close and could end up ruing his missed chances.
Arsenal thought they had won a second penalty when substitute Eze went down under a sluggish Hancko challenge but the referee changed his mind after a VAR review, deciding the Slovakian defender's contact was minimal.
Arsenal next take on Fulham as they continue their battle with Manchester City for the Premier League title, while with little to play for in LaLiga Simeone will rotate heavily, before this tie is decided in London.