Daniel Podence's close-range finish earned Wolves their first Premier League win of the season at the expense of Southampton.
Podence broke the deadlock in added time at the end of a poor first half, sending an unorthodox finish past Saints goalkeeper Gavin Bazunu from Matheus Nunes' low delivery.
Che Adams thought he had restored parity after Joe Aribo's cross was deflected into the Southampton striker's path by Wolves goalkeeper Jose Sa, but Adams used his arm to bundle the ball over the line and the goal was correctly disallowed by referee John Brooks.
Adams - making his 100th Premier League appearance - then headed Stuart Armstrong's looping delivery against the crossbar as Southampton pushed for an equaliser, but to no avail.
The victory lifts Bruno Lage's side out of the bottom three, while Southampton drop into the bottom half.
Lage later said: "It's important for us, but the most important is what we are doing in each moment. Players are arriving, we don't have time to train and have to put them straight into the games. We try our best to have our best strategy and they're performing well.
"We scored one goal and after that we were very brave in the way we defended. We're very happy. I told the players it's one win, we have to build on it. We need to practice. The team that finished pre-season and the team we have now are so different.
"I had a feeling when the fans started singing at the start about 'Bruno Lage ball'. I told the players we have to go outside and give everything. The big attitude and the big energy comes from the fans. That's why I was there at the end of the game to take all the support from them."
On Sasa Kalajdzic's half-time withdrawal, he added: "He felt something. Nothing special, but we went with Guedes.
"With Raul it is normal fatigue. He didn't do pre-season and played straight away. With a good pre-season, he'd be able to play without problems, but not without pre-season. Today it was impossible for him to run - chronic fatigue. Because of that we started with Sasa."
