Sadio Mane scored a hat-trick as Southampton thumped Manchester City 4-2 in the Premier League on Sunday.
The Saints raced into a two-goal lead inside half an hour at St Mary's as Shane Long and Mane struck, before Kelechi Iheanacho headed City back into the game just before half-time.
But Mane netted twice more after the break to leave City looking over their shoulders again in the race for the top four. They are now just four points ahead of Manchester United with two league fixtures left to play, while Louis van Gaal's side have a game in hand. Southampton, meanwhile, climbed back above Liverpool into seventh, boosting their hopes of Europa League qualification in the process.
One bright spark for City, however, was the performance of Iheanacho, who netted a stunning late consolation to make it four goals in two games for him on an otherwise dreadful day for the away side.
Manuel Pellegrini made eight changes to his side with Real Madrid in midweek in mind, and it showed in their disjointed performance for most of the first half.
Time and time again City conspired to lose the ball in dangerous areas, with Fernandinho and Fabian Delph particularly culpable, and only a lack of incision in the final third stopped Southampton from taking the lead sooner.
After 25 minutes, though, they did make it 1-0, and it was a fine move as Cuco Martina pinged a ball into Dusan Tadic over the top, before he pulled it back into the path of Long. There was still work for the Irishman to do, with a few yards to make up on Nicolas Otamendi, but Long simply wanted it more and beat the City defender to the ball before poking it past Joe Hart.
And less than three minutes later, Hart was beaten again. This time, a fine counter-attack saw Victor Wanyama pick out Tadic, who waited and waited before threading a fine pass into the path of the onrushing Mane, who slammed it home at the first time of asking.
City were sorely lacking going forward, with the likes of Raheem Sterling and Wilfried Bony struggling to make an impression, but on the stroke of half-time they managed to get a foothold in the game through Iheanacho.
The 19-year-old forward, starting his second Premier League game in a row after netting two against Stoke last week, pounced to head home from six yards out after Samir Nasri's ball in had ricocheted off a couple of Southampton defenders and fallen into his path.
It was a lifeline City scarcely warranted, and Saints deservedly restored their two-goal lead in the 57th minute as Mane netted from close range after Virgil van Dijk's header from a corner had crashed off the bar - via the top of Hart's head.
And 11 minutes later, he completed his hat-trick, again latching onto a Tadic pass before firing low inside the near post from just inside the area.
There was more drama to come, however, as Iheanacho added a fine second for himself and City with a goal that deserved far more than just consolation status.
The Nigerian picked up Jesus Navas' pass just inside the area, before taking a touch and curling an absolute peach past the helpless Fraser Forster and into the top corner.
City still had 11 minutes to find their way back in, but never really threatened again, and Pellegrini and Co will hope to forget about this one as soon as possible before attention turns to Wednesday night and the Bernabeu.
Southampton: Forster (6), Martina (7), Fonte (7), Van Dijk (7), Bertrand (6), Clasie (7), Wanyama (8), Davis (7), Mane (9), Tadic (9), Long (8)
Subs: Rodriguez (n/a), Romeu (6), Ward-Prowse (5)
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Man City: Hart (5), Zabaleta (4), Otamendi (3), Mangala (3), Kolarov (4), Delph (3), Fernandinho (3), Nasri (5), Sterling (4), Iheanacho (8), Bony (5)
Subs: Demichelis (5), Navas (6)
Man of the match: Sadio Mane