Bournemouth won at St Mary's for the first time as they beat Southampton 3-1 in the Premier League, sending them into third in the table.
The Cherries had failed to win at their south coast rivals in 15 attempts, but they got off to the perfect start when Nathan Ake headed home inside 10 minutes before Harry Wilson (35) fired the ball home to double their lead.
Southampton were much improved in the second half and pulled one back inside seven minutes as James Ward-Prowse (53) scored a smashing penalty. They kept piling on the pressure but a calamitous error between Jan Bednarek and goalkeeper Angus Gunn with seconds to play allowed Callum Wilson (90+4) to score into an open goal.
It was a second successive victory for Bournemouth, as they catapulted from ninth place into third ahead of the weekend games, while Southampton fell to 11th from tenth.
How Bournemouth earned their maiden St Mary's win
Southampton were slow out of the traps as Bournemouth opened the scoring inside ten minutes. It was a thunderous header from Ake, who powered in front of Kevin Danso to send Diego Rico's corner into the back of the net.
15 minutes later, and it looked like the visitors had added another - but were thwarted by VAR. Dominic Solanke slotted the ball through for Josh King, who floated it past Gunn and into the top corner. However, the goal was reviewed by VAR and showed that King's foot was offside in the build-up, thus disallowing his effort.
Southampton: Gunn (5), Cedric (6), Danso (5), Vestergaard (6), Bednarek (5), Hojbjerg (6), Ward-Prowse (7), Romeu (7), Boufal (7), Redmond (6), Adams (6).
Subs used: Bertrand (6), Ings (6), Armstrong (n/a).
Bournemouth: Ramsdale (7), Rico (6), Stacey (7), S. Cook (8), Ake (7), Lerma (6), Billing (7), H. Wilson (7), King (8), Solanke (7), C. Wilson (7).
Subs used: Fraser (6), L Cook (6), Surman (n/a).
Man of the match: Josh King.
But it didn't take long for Bournemouth to find the net again as Harry Wilson scored his third goal of the season in the 35th minute. Phillip Billing darted down the left flank before cutting the ball back for Harry Wilson, waiting inside the area. Jannik Vestergaard could not quite get there as the winger guided the ball home with Southampton unable to find a second reprieve.
The start of the second half saw a turnaround in fortunes for the Saints as they were awarded a penalty seven minutes after the break. Che Adams was clipped by Steve Cook's outstretched leg as referee Chris Kavanagh pointed to the spot, with a brief VAR check confirming his decision. Ward-Prowse stepped up and hammered the penalty home as Southampton cut their deficit in half.
- Moussa Djenepo was replaced by Nathan Redmond for Southampton in one of two changes, with Maya Yoshida also replaced by Kevin Danso in defence.
- Bournemouth made one change with Lewis Cook dropping to the bench, being replaced by Jefferson Lerma. Ryan Fraser also started on the bench once again.
A few minutes later, and there was another VAR review as King went tumbling over in the area after a challenge from Cedric Soares, but the referee waved away the claims. Once the ball had gone out of play, VAR stepped in to have a look but concluded that the initial decision from Kavanagh would stand.
Southampton continued to press for the equaliser as the second half wore on and their best chance came with nine minutes to play. Danny Ings cut the ball back for Ward-Prowse in the middle and his scooped effort was spilled by Bournemouth goalkeeper Aaron Ramsdale. Luckily, it fell into the path of Steve Cook, who managed to hoof the ball away before Ward-Prowse could pounce again.
But it was a catastrophic error from Southampton that gifted Bournemouth a third goal with the last kick of the game. Gunn came racing to the top of his box as, under pressure from Callum Wilson, Bednarek tried to play the ball back to him. However, the ball wriggled free amongst the confusion and allowed the striker to pounce, driving towards the open goal and slotting home to seal the win.
Man of the match - Josh King
It was a rather unlucky game for King. He performed superbly and did have the ball in the back of the net, although VAR ruled it out for a very tight offside call. He was also denied a penalty, despite an offence appearing to have been committed, but his work rate remained second to none.
On co-commentary, Jamie Carragher said: "He's been a constant threat. He's not been lucky enough to get a goal, but he caused huge problems for Southampton in the first half. The man he was up against was taken off at half-time and in the second half, he has been the one constant threat for Bournemouth."
Southampton manager Ralph Hasenhuttl: "We lost the game in the first half. We weren't good for the first 20 minutes or so and had to change the shape twice. We've moved to 4-3-3 and it was a lot better.
"In the second-half, we had every second ball and were very sharp. I think we have 26 shots on goal to six from Bournemouth, but in the end the most important stat is the goals.
"We weren't aggressive enough, and the opponent was very clinical. That was the big difference today. We had a lot of blocked shots, a good performance in the second half but without the result.
"We showed a good reaction in the second half, and had 64 per cent possession. Nathan [Redmond] had a big chance to equalise but today we didn't deserve to take anything because the first half wasn't good enough."
Bournemouth manager Eddie Howe: "It was an historic game for us tonight. I don't think we were at our very best and we were loose at times, but what we did show was real heart, fight, determination and desire. We defended heroically at times, our goalkeeper played very well. It wasn't the perfect performance but we're delighted with the win.
"At 2-1 and the manner we conceded as well, followed by the VAR psychological blow, you can start to feel sorry for yourself, but we didn't. Although we conceded chances, I feel that was down to the general performance which wasn't what we wanted it to be.
"Some of our attacking play was really good, but we could've been punished on another day. In part that's down to how we play, so you have to take the rough with the smooth. We no longer have an inferiority complex as I feel we had when we first arrived in the league."
- Of ever-present Premier League sides since the start of last season, Southampton have kept fewer clean sheets at home in the competition (three in 22 games at St. Mary's) than any other side.
- Bournemouth have won four of their last eight away league outings (D1 L3), this after having lost nine in succession on the road beforehand.
- Since the start of last season, Callum Wilson has been directly involved in 16 goals away from home in the Premier League (11 goals, 5 assists), more than any other player.
Southampton have another derby to contend with on Tuesday as they travel to Portsmouth in the Carabao Cup, live on Sky Sports, before visiting Tottenham on Saturday in the Premier League. For Bournemouth, they make the trip to Burton Albion on Wednesday in the Carabao Cup before welcoming West Ham in the Premier League on Saturday.