Burnley manager Sean Dyche praised Joey Barton's attitude after the midfielder scored on his Premier League debut for the club, but described the match-winning free-kick as "a lucky finish".
Barton scored from 25 yards just five minutes after being introduced as a second-half substitute as the ball crept underneath Southampton's wall before bouncing into the net.
Dyche cast doubt on Barton's claim that he picked his spot and hit it, but also credited the 34-year-old's fitness and attitude since arriving at Turf Moor for a second spell with the Clarets.
"Joey affected the game, but I thought all the subs did well," said Dyche. "I wasn't sure he was going to take it but he's not lacking in self-belief.
"It was a good finish. A lucky finish, but he's looked at the wall and he said he has seen a gap and threaded it through. I'm not quite sure it plays out that way, but we'll take the win.
"He's come back here, he's really fit, he's looked after himself and he wants to do well for us. The rest will take care of itself."
Barton's introduction was in part prompted by an injury to Dean Marney, who was left requiring treatment on the same day forward Patrick Bamford returned to parent club Chelsea after his loan at Burnley was cut short.
Dyche didn't seem unduly worried by Marney's injury, saying: "Dean has had some tightness in his hamstring and it just flares up a bit at times, so we had to get him off."
The result left Southampton manager Claude Puel to reflect on a fourth consecutive Premier League defeat – one that he felt his side did not deserve.
Southampton beat Liverpool in their EFL Cup semi-final, first leg in midweek, and, after they failed to convert a number of good chances against Burnley, Puel said: "We didn't deserve to lose. It was a strong game for us against a physical team playing long ball.
"It was a fight and I think we gave them a good answer, with many chances. The free-kick was sufficient to win this game and it's a shame because we played well.
"We tried to play and had many chances. It was the same game and spirit and attitude as we had against Liverpool, but without scoring it is difficult to win.
"It was a strange free-kick but it was sufficient. It is difficult to accept this. It's strange to lose this game with all the chances we had and with so few opportunities for the opposition, but this is the Premier League."