UEFA said the correct decision was made to disallow Julian Alvarez's penalty in Atletico Madrid's Champions League loss to city rivals Real Madrid on Wednesday but European soccer's governing body would enter discussions to review the rule.

A livid Atletico enquired with UEFA after Alvarez had his shootout penalty ruled out by the referee in their last-16 tie that saw Real reach the quarter-finals of Europe's elite club competition.

Argentine forward Alvarez slipped and the VAR spotted that his left foot touched the ball slightly before he kicked it with his right. With only one touch permitted, the penalty, which would have levelled the shootout at 2-2, was chalked off.

"Although minimal, the player made contact with the ball using his standing foot before kicking it," UEFA said in a statement on Thursday.

"Under the current law (Rules of the Game, Law 14.1), the VAR had to call the referee signalling that the goal should be disallowed.

"UEFA will enter discussions with FIFA and IFAB (International Football Association Board) to determine whether the rule should be reviewed in cases where a double touch is clearly unintentional."

Atletico did not immediately respond to a request for comment on UEFA's statement, though coach Diego Simeone was livid on Wednesday with Polish referee Szymon Marciniak's decision.

"I've never seen the VAR called to review a penalty in a shootout ... Never!" the Argentine said at the post-game press conference.

"Did you see him touching the ball twice? Please whoever was present in the stadium and saw him touching the ball twice, the ball moving, please come forward and raise your hand!

"I don't see anybody with their hand raised so that's all I have to say ... next question."

Atletico fans were similarly outraged.

"It's so clear that they want Madrid to go through," one supporter posted on social media platform X.

"Football will never see anything like this again," wrote another. "A historic robbery has taken place at the Metropolitano with the whole world watching."

Some suggested Alvarez should have been given a chance to retake the penalty.

"Cancelling a penalty because there might have been a double touch is abhorrent," one supporter wrote on X. "There's no other way to put it: it's anti-football."

Meanwhile, Atletico Madrid will have to pick themselves up as they prepare to host Barcelona in a top-of-the-table LaLiga clash tomorrow after a heartbreaking and controversial shootout defeat to rivals Real Madrid in the Champions League on Wednesday.

Atletico boss Diego Simeone was left fuming with the referee's decision to rule out Julian Alvarez's spot kick for a double touch, with Madrid going on to win the shootout 4-2 and book their spot in the quarter-finals.

Alvarez slipped as he struck the ball, with the VAR immediately informing the referee of a double contact, but Simeone was unconvinced, saying that he had yet to see an image that conclusively showed that the player had touched the ball twice.

While Wednesday's result was a gut punch for Atletico, Simeone said he hoped they could recover quickly for tomorrow's game against title rivals Barca.

"We'll see if this defeat will cost us moving forward, the way we went out it's not easy to digest," Simeone said on Wednesday.

"I'm sure Barca wanted us to go to extra time. We will get to the game tired, beaten after we competed the way we had to compete tonight, but we'll give it everything we've got on Sunday."

Only one point separates Spain's three biggest clubs in one of the closest LaLiga title races in recent years with Barca leading the pack on 57 points, ahead of second-placed Real Madrid on goal difference with Atletico in third on 56 points.

Barca have a game in hand over both and a win in the Spanish capital tomorrow would leave them in control of their own destiny as they approach the final stretch in a promising season in which they remain in contention for three major trophies.

Barca maintained their imperious form with a commanding 3-1 win over Benfica in the Champions League on Tuesday to extend their unbeaten run to 17 games across all competitions.

They are set to face Borussia Dortmund in the quarter-finals while they have also reached the Copa del Rey semis in which they drew 4-4 with Atletico in the first leg before the April 2 return.

Real Madrid will play at Villarreal today and could go provisionally top of the table, heaping pressure on their title rivals.

Like Barca, Carlo Ancelotti's Real are also in contention for the treble. They are in a good position to reach the Copa del Rey final, after having beaten Real Sociedad 1-0 in the first leg of their semi, and are set to face Arsenal in the Champions League quarters.