Substitute Sadio Mane made amends for missing a penalty by netting a double to help Southampton battle from two goals down and beat Liverpool 3-2 at St Mary's in a Premier League thriller.
The Senegal international was only available to manager Ronald Koeman after having his red card against Stoke City last weekend overturned and put in a dramatic performance after coming off the bench at half-time.
Mane first failed to convert a spot-kick shortly after the interval before atoning halfway through the second half by pegging back the visitors.
Graziano Pelle levelled for Southampton with seven minutes left and there was more drama to come as Mane scored the winner in the 86th minute.
Liverpool - who were without the injured Roberto Firmino and Jordan Henderson - looked to be cruising at 2-0 up thanks to goals from Philippe Coutinho and Daniel Sturridge in the first half, but were left to rue what could have been as their top-four ambitions took a major blow.
Virgil van Dijk headed just wide in the sixth minute after a dangerous corner from the left, before Shane Long was unfortunate not be handed a penalty after he was seemingly brought down inside the area by Dejan Lovren.
Pelle then volleyed over the crossbar after a quick one-two with Steven Davis, with Long's shot blocked by Lovren shortly after as Southampton pushed hard for the opener.
Yet it was Liverpool who went a goal up against the run of play when Coutinho found the net in the 17th minute. The Brazilian picked up the ball down the left after Southampton lost possession in midfield, cut inside and beat Fraser Forster with a sublime long-range strike that curled low beyond the England goalkeeper.
Things got even worse for the home side five minutes later as the visitors struck again via Sturridge. Divock Origi set up his fellow forward inside the box after yet another quick breakaway and Sturridge beat Forster with a left-footed strike into the far corner.
Liverpool continued to cause Southampton all kinds of trouble with their counter-attacks and Forster came out on top after a one-on-one with Joe Allen.
Allen thought he had made it 3-0 in the 33rd minute when he fired home after a corner, only for the referee Roger East to disallow the effort for offside.
Southampton had the perfect chance to pull one back early in the second half when East awarded them a penalty following a foul from Martin Skrtel on Pelle, but Simon Mignolet pulled off a superb save to deny Mane from the spot.
Mane, however, did find a way past Mignolet just after the hour. A poor touch from Jon Flanagan allowed Pelle to set up the Senegal international inside the area and he scored with an emphatic finish into the right corner.
Christian Benteke, who had come on to replace Sturridge, missed a gilt-edged opportunity to restore his side's two-goal lead when he fired just wide with 15 minutes left.
The hosts fought hard and were eventually rewarded for their courageous display in the 83rd minute when Pelle shot home from the edge of the box to make it 2-2.
The home fans were sent into raptures when Southampton netted a winner as Pelle eventually found Mane following a poor clearance from Mignolet and he coolly slotted in to complete an incredible comeback that prompted Koeman to charge down the touchline and celebrate with his players.