Atletico Madrid suffered their first major setback of the season as they lost 2-0 at Celta Vigo after defender Stefan Savic was sent off midway through a miserable second-half performance by Diego Simeone's side on Saturday.

Celta’s Uruguayan striker Maxi Gomez put the Galicians ahead straight after the break when he pounced on a slip by compatriot Diego Godin and Iago Aspas doubled the lead in the 52nd minute with a header the day after being dropped from the Spain squad by new coach Luis Enrique.

Things got worse for Atletico after 70 minutes when their Montenegro defender Savic was dismissed for a second booking and a minute later they thought they had conceded again when Gustavo Cabral scored but the goal was ruled out for offside after consultation with the video assistant referee (VAR).

Atletico have four points from their opening three games and could slip five behind Real Madrid, who were hosting Leganes later on Saturday, and Barcelona, at home to Huesca on Sunday, if their rivals win their respective weekend fixtures.

"I'm not worried about this result, I'm calmer than ever, because this is a wake up call for us. I've no doubt this is the best thing that could happen for us," Atletico coach Simeone told reporters.

"We didn't play well, Celta were lethal, while we had chances at the end of the first half which we could have done better from. We didn't take them and in the second half they killed the game off in five minutes and they deserved to win."

Celta's Argentine coach Antonio Mohamed said the result should make his side realise what they are capable of.

"To beat a team as great as Atletico you have to play a perfect game and that's what we did. Today should motivate us to believe in ourselves and believe that we can do great things," added Mohamed, whose side have seven points after three games.

"This is a very tough league but we will keep improving. This win is a huge boost in confidence for us."