An own goal by Tomas Hubocan consigned Russian champions Zenit St Petersburg to a cruel 3-2 defeat in their Champions League group match with AC Milan here on Wednesday.
Zenit - who have been riven by internecine discord over the wages being paid to big money signings Hulk and Axel Witsel which has led Russian national captain Igor Denisov to being dropped - had done well to level the game after being 2-0 down early on.
Defeat, though, leaves them pointless in the group while Milan's win eases the pressure on Massimiliano Allegri after a disappointing start to the season in Serie A and sees them move onto four points after two games.
Malaga - who beat Zenit in the opener a fortnight ago - play Anderlecht, who began with a creditable 0-0 draw in Milan, later on Wednesday.
"It's a very important win for us," Allegri said. "It was not easy to beat Zenit on their home turf. After we scored twice we had to resist very serious pressure. Our goalkeeper played very well.
"I consider Zenit to be a club which is in the vanguard of European football from any point of view."
Milan hit the hosts with two goals in three minutes as first Urby Emanuelson's freekick took a huge deflection off Roman Shirokov and left Zenit 'keeper Vyacheslav Malafeev stranded.
Emanuelson was to go close seconds later as he ghosted in at the backpost but the Dutch international went with his preferred left leg when the right would have been the better option and it went the wrong side of the post.
However, the visitors doubled their lead in the next attack with a superb solo run by Stephan El Shaarawy as the youngster, who turns 20 later this month, rode two tackles and beat a one-paced defence to slot the ball past Vyacheslav Malafeev for his fifth goal in four games.
Zenit rallied and but for several brilliant saves by Milan 'keeper Christian Abbiati - especially from a header by Shirokov and Hulk - in the last 10 minutes of the half they could have gone in level at half-time.
Hulk had done his popularity with his team-mates little good earlier in the half when he produced a storming run but opted to shoot instead of looking up and seeing Alexander Kerzhakov, one of the players most upset with his and Axel Witsel's huge wage packets, who was unmarked in the penalty area.
However, he made up for that oversight as he got free on the left side of the area in time added on in the first-half and made no mistake shooting into the far corner giving Abbiati no chance.
The hosts maintained that momentum right from the start of the second-half and drew level in the 48th minute as Shirokov headed home from Hulk's corner - Abbiati's indecision as to whether to come for it or stay on his line proving fatal.
The hosts bad luck, though, continued as having fought back to level terms they were undone by another deflection this time it went down as an own goal to Hubocan.
His knee connected with a tame effort by Giampaolo Pazzini and wrongfooted Malafeev to restore Milan's lead and they held on to pile the misery on the Russian side.
"It's a very sad evening for me," said Zenit head coach Luciano Spalletti. "This defeat ruined the work that we were doing for so long. Unfortunately we lost this match.
"We started the match badly again. My players avoided responsibility and, like what happened in Malaga. we conceded two early goals.
"The Champions League is a completely different competition if compared to the Russian championship. You need to perform solidly throughout the match and be more skilful and crafty but we failed to tick those boxes."