Cyle Larin scored his fifth goal of the season as Southampton beat Swansea 3-1 to humble a table-topper for the second home match in a row.
Larin, who is the joint-top scorer in the Championship, netted either side of Finn Azaz and Leo Scienza strikes to make it 13 games unbeaten at St Mary's in a row.
It followed Saints hammering previous leaders Millwall 5-1 10 days ago, although Swansea - who netted through Zan Vipotnik's penalty - stayed level on points at the summit.
Swansea made five changes from the side which drew with Wrexham at the weekend and failed to have a shot on target in the first half - with the majority of their efforts blocked long before reaching Daniel Peretz.
On the other hand, the hosts were rampant as they eased through the Swans' lines.
Scienza and Ryan Manning were the first to find open spaces behind their opposition in the fourth minute, but after their neat interchange, Azaz skied high into the stand.
But five minutes later the Republic of Ireland international found the bottom corner with a low left-footed shot, after Flynn Downes had powered through.
It was Azaz's first goal in seven attempts against Swansea, his second of the season, and just the second goal the Swans had conceded in 2026-27.
Larin was the second player to go from putting supporters in the Chapel Stand at risk before scoring.
The Canadian snatched at a half-volley after a corner in the 25th minute, before sliding home eight minutes later.
This time James Bree had made the run in behind the porous defence before squaring to Larin for his fifth league strike of the campaign, after two blanks.
Midfielder Downes had an opportunity to completely put the game to bed two minutes before the interval but he hooked over the crossbar after a Larin knockdown.
Swansea boss Vitor Matos sent winger Ronald on at half-time and he brought immediate energy by bundling a shot over.
It was contagious for the away side, and within 10 minutes of the restart they had pulled a goal back.
Bree pulled back Vipotnik at the back post before the Slovenian picked himself up to fire into the bottom left corner from the spot - his seventh straight penalty success.
Despite a far more even balance of play, Southampton still had the better chances, as Keven Schlotterbeck's poke forced a good save and Larin's improvised header bounced narrowly wide.
And Scienza - who had seen a lashed shot battered away - secured the three points 12 minutes from the end by calmly slotting into the corner after being released by Kuryu Matsuki.
Southampton's Tonda Eckert:
"We played the top of the league today and there are different approaches to those games.
"We decided to go very brave today and I think that was important.
"Swansea start games with a lot of intensity and we wanted to match that and we came out on top. The boys did that in an outstanding manner from the start and then we were 2-0 up.
"We had the courage to play and that is what I told the boys that is what I was proud of today.
"For the quality we have high up the pitch, we have to get them involved in plenty of situations. It is very hard to stop those boys.
"We have to keep backing it up at home game after game. If I start talking out about how strong we are at home we could have problems against Bristol City on Saturday.
"We have to do it again and then do it again and then again. The reality is the crowd is fantastic and the ground staff are doing an unbelievable job to keep the pitch in such a great condition."
Swansea's Vitor Matos:
"Southampton were the better team tonight. We lacked our intensity and aggressiveness in the first half that gave them the initiative.
"Southampton punished us with two goals and then in the second half we were much more aggressive and tried to push them deep and that allowed us to arrive with more quality.
"You never like to lose and there are always negatives but they are only negatives if you don't improve from them and understand why.
"We need to understand what happened and how we can be more competitive."
