Brighton claimed a vital victory in their quest to avoid relegation from the Premier League and left stuttering Southampton still nervously looking over their shoulders.
Leandro Trossard's emphatic finish settled an entertaining Sunday lunchtime south-coast contest, Danny Welbeck's deft touch freeing the Belgium winger to stride into the box and lash home.
The Seagulls had taken an early lead through skipper Lewis Dunk's powerful header from a corner before Che Adams' close-range volley ensured the Saints headed in level at the break.
Adams came closest to a second equaliser for Southampton, still without injured leading scorer Danny Ings, but he was brilliantly denied by the outstretched leg of Brighton keeper Robert Sanchez.
Victory halted a three-game losing streak for Graham Potter's Seagulls, who climb a place to 16th above Newcastle, three points clear of 18th-placed Fulham and with a game in hand.
Afterwards, Trossard remarked: "It was very important. Finally we got what we deserved. We were the better team overall and finally we got the three points. It's a relief and now we can build on that.
"It's always nice to score a goal, especially in this game we we needed those three points.
"You always try as a team to score goals, we created a lot of chances this season already, we didn't convert them unfortunately but today we scored two and won the game, so we are really happy."
On Adam Lallana's influence, he added: "He's an important player. He's experienced, has great quality on the ball and we need him as a team. He's added that extra bit for us and we are really happy to have him."
