Charlie Austin scored a late winner for Southampton as they beat Arsenal in a five-goal thriller at St. Mary's for Ralph Hasenhuttl's first win as manager.
Danny Ings scored twice for the Saints, with Henrikh Mkhitaryan scoring a brace for the Gunners as well.
Ings gave Southampton an early lead with a headed goal, before Mkhitaryan equalised in a similar fashion. Ings then scored his second header and Arsenal hit back in the second-half after a huge deflection from Mkhitaryan's low shot.
Austin, who replaced Ings late on, headed home after Shane Long's excellent cross to finish off a brilliant Saints counter-attack.
Arsenal stay in fifth place, now two points behind Chelsea, who won at Brighton - whereas Southampton have moved up a place to 17th, and out of the drop zone taking over Huddersfield and Burnley in the process.
How It Happened
Southampton were coming into this game without a win in 12 league games and anything but three points would break a club record for the Saints.
However, they started this one excellently and that would have eased the nerves of Hasenhuttl in the Southampton dugout.
Matt Targett delivered a pinpoint cross for Ings, who powerfully headed past Bernd Leno to give the hosts the lead on 20 minutes.
Arsenal hit back soon after, though, and Nacho Monreal delivered another great cross and Mkhitaryan was there to score the second header of the match.
But just as Arsenal looked to settle down in the game, Ings was on hand to punish them once again. This time, Nathan Redmond's cross was headed in by a superb Ings.
Arsenal's poor first-half record continued and they'd need to replicate their second-half form to stand any chance in this game.
The Gunners made a half-time change: with Hector Bellerin being replaced by Alexandre Lacazette, and a switch to a back four for Unai Emery's side.
Soon after the restart, the sub must've worked. Mkhitaryan's shot took a huge deflection off Jannik Vestergaard and completely threw off Alex McCarthy.
Ings was taken off with just under 20 minutes to go as he continues his return to full fitness, with Austin replacing the striker.
Long thought he had won the game for Southampton, when he poked home a real scramble in the Arsenal box - but Sian Massey had her flag up on the far side for offside.
But Southampton continued to press; perhaps being influenced by Hasenhuttl's takeover, with the Saints very reluctant to attack in recent times.
Long's cross with just under five minutes remaining of normal time, was met by Austin at the far post - with Leno completely missing it - much to the joy of the jubilant St. Mary's crowd.
Arsenal did their best to bounce back, but they never really threatened McCarthy with not too much time to do so and Southampton had their first win in 12 league games, and their first under their new manager.
The Managers
Southampton manager Ralph Hasenhuttl described the performance against Arsenal as "amazing" and was very proud of their efforts.
"It's amazing what the team can do in a week," the new Saints boss said. "It was very intensive, we had time to work on the basics and built the fundamentals for our game.
"I'm very proud of how focused and uncompromising they were, and when they had the chances, how merciless they were.
"It was a fantastic atmosphere and a special feeling here to win the match."
Arsenal boss Unai Emery said that if his side play like they did against Southampton, then they won't find themselves in the top four.
"We could have lost at any time and it was today," Emery said. "If we won't win like today, we cannot be in the top four.
"After 22 matches unbeaten we didn't lose and we are only fifth position in the table and the reason is because other teams are very well.
"Other teams usually they are winning but we need to do our way and continue to build. The objective is therefore top but we know it's not easy because the other teams are playing at a high level. We need to be very, very demanding."