Finn Azaz's first-half strike was enough to secure a 1-0 victory over Norwich and send Southampton into the Championship play-off places for the first time since the opening weekend.
Forward Azaz pounced on a quickly-taken throw-in during the first half to slam home the only goal of the match at St Mary's.
But Saints had goalkeeper Daniel Peretz to thank for the three points - and a 13th game without defeat - after a season-best seven saves, including a sensational double-stop in the second half.
The Canaries are now nine points adrift of the top six as their promotion hopes hang by a thread, despite 11 wins in their last 14 matches.
A cagey start was punctuated by a pair of strong saves at either end by Peretz and then Vladan Kovacevic.
Southampton's Israeli goalkeeper Peretz smartly got down to his right to deny a thumping effort from Anis Ben Slimane.
And then Norwich's shot-stopper Kovacevic parried away James Bree's sweetly-struck half-volley.
Sam Edozie had put the rebound in after that chance, only to see the offside flag go up against Azaz, but less than a minute later Saints had the ball in the back of the net for real.
Bree quickly took a throw-in before the Canaries could reset, Kyle Larin nodded on before Azaz latched on to crash into the roof of the net.
The Republic of Ireland international celebrated his 10th goal of the season the day after St Patrick's Day. It was the first goal the visitors had shipped away from Carrow Road since the end of January.
Norwich have not won after conceding first on the road this season but were a whisker away as Mathias Kvistgaarden could not get a toe to Paris Maghoma's wicked cross from the right.
Peretz was forced into another save 12 minutes into the second half when he denied a snapshot from Slimane.
If that had been a regulation save, his low dive to keep out Kenny McLean's stinging drive was far from it, as the visitors looked the more likely to score the second goal of the match.
The on-loan Bayern Munich goalkeeper outdid himself again with a double save to deny Ali Ahmed and then Kellen Fisher from point-blank range.
Peretz now has more clean sheets than goalkeepers before his arrival - Gavin Bazunu and Alex McCarthy combined. This his fifth in 12 appearances in the league.
Substitute Shea Charles almost killed off the match, but his low bottom-corner-bound shot was push away by Kovacevic.
Norwich almost had a 98th-minute equaliser but Jack Stephens' inadvertent foot towards his own goal came back off the crossbar, before Peretz made one last stunning save to keep out Ruairi McConville.
Southampton's Tonda Eckert:
"That was a tough one. There is a reason why they have won 10 of the last 13 games.
"It is nice. It is always nice to take step after step but you have to play until the end.
"There is still a lot of games coming up, things can go so fast in either direction. We have done well to keep our head down and maintain a level of humility.
"It is very important not to look too far ahead. We have done well not to get carried away with the negatives or positives. That isn't going to change."
Norwich's Philippe Clement:
"I am not a dreamer, that is for the fans. I made that mistake in the first 15 years of my career.
"It is of no use to look at the rankings. We have no control of what other teams will do. It is about our performances and then we will see where we are in the last two or three games.
"It is already amazing that so many people talk to me about play-offs when in November the club had nine points.
"Everyone could see we deserved more from this game.
"It is football that you lose this type of games and there is a reason their goalkeeper is the man of the match.
"I am more proud of the team than gutted about the loss. It didn't happen much that I have told the team I am proud of them."
