Goals from Adam Lallana and Jay Rodriguez helped Southampton to victory over Swansea and into the Premier League's top four.
Lallana fired high past Michel Vorm early on, before Saints keeper Artur Boruc saved brilliantly from Michu while Nathan Dyer struck the post.
Swansea rallied after the break, but Rodriguez's late volley sealed the win.
It was a third consecutive win for the Saints, while Swansea have won only one in four and fall to 15th.
Pochettino 'delight' at Saints start
More broadly, Mauricio Pochettino's Saints have lost only three of their last 19, and have the tightest defence in the top flight, conceding only two goals this term.
Meanwhile, Swansea, playing their seventh game in 20 days, have lost on all four occasions that they have conceded the opening goal this season, though they may curse their luck after Dyer's first-half strike rolled across the goalline after hitting the post.
Dyer's effort was the closest Swansea came to scoring, but it was his old club who started the game sharply, with the trio of Rickie Lambert, Pablo Osvaldo and Lallana linking neatly.
Osvaldo went close from a tight angle, before Lallana went one better in the 20th minute.
The 25-year-old followed his own cross into the box and, after a botched clearance, was fed by Steven Davies to power the ball high into Vorm's net from 10 yards.
It was the first time the Saints had scored a first-half goal in the Premier League this season and it helped make for a more open game.
Saints in mean mood
Southampton have conceded two goals in their opening seven top-flight games. The last time they did that was in 1983-84, when they ended the campaign in second place, behind Liverpool.
Michu, who wore a headguard after being kicked in the
Europa League win over St Gallen
, led the Swansea response and headed at the back post to draw a fine save from Boruc, while Jonjo Shelvey had an effort from distance saved.
Michael Laudrup's Swans, chasing three consecutive top-flight away wins for the first time in 31 years, grew into the game and Dyer rattled the woodwork to start a 15-minute spell of pressure at the end of the first half.
He collected Wilfried Bony's back-heel to fire left-footed against the woodwork, only for the ball to roll across the line.
Bony himself was then denied as a header was brilliantly parried by Boruc before Michu headed straight at the Polish keeper.
Swansea's momentum was not hampered by the interval and Dyer - so often their first-half supply line - dragged a shot wide, but Saints did not concede a goal in September and absorbed the visiting pressure.
And, with a little over 10 minutes remaining, the hosts thought the points were sealed when Victor Wanyama bundled home from a corner, but referee Mike Dean had spotted shirt-pulling in the build-up.
The decision kept the Swansea hopes alive temporarily and Michu missed a headed chance from 10 yards before Rodriguez wrapped it up for the hosts.
Swansea deserved more - Laudrup
A long clearance from Boruc created chaos at the heart of the City defence and, when Chico and Jordi Amat failed to deal with the bouncing ball, Rodriguez volleyed home.
Southampton manager Mauricio Pochettino:
"There were different phases of the game where we commanded and then they did, but overall I'm delighted for the three points and it sets us up for the international weeks and the game against Manchester United.
"I don't know where we will finish, I don't have a crystal ball. The most important thing is to look to the next game and focus.
"Osvaldo is fine, he took a heavy challenge but taking him off was mainly a tactical challenge."
Swansea City manager Michael Laudrup:
"We performed very well. Apart from the first 15 minutes we dominated the game and had lots of chances.
"They got a good goal but the whole of the second half was all about us. We still need too many chances to score. After the St Gallen game, I said they deserved a little more. Today, I think we deserved a little more."
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