Southampton secured a place in next season's Europa League after goals from Sadio Mane, Graziano Pelle, Ryan Bertrand and Steven Davis saw them thrash Crystal Palace 4-1 at St. Mary's on Sunday.
Ronald Koeman's men were seventh heading into the encounter, but they leapfrogged West Ham following their failure to beat Stoke City.
The home side were on top from the outset as Palace manager Alan Pardew rested several first-team regulars ahead of next week's FA Cup final against Manchester United, but it took them until the closing stages of the first half to open the scoring, with Mane netting his 15th goal of the season in all competitions.
Pelle doubled Saints' lead after the break, only for Jason Puncheon to pull one back for the away side against his former team.
Southampton were not to be denied, though, as Bertrand converted a penalty, before Davis added a fourth with three minutes to go.
The hosts dominated the early stages with Palace pinned back in their own half, but the visitors were the first to threaten when Dwight Gayle called goalkeeper Fraser Forster into action with a shot from the edge of the area.
Dusan Tadic attempted to rally Southampton and the Serbia international did well to set up Mane in the 23rd minute, with the attacker firing just wide after beating Adrian Mariappa to the ball.
Shane Long was then unfortunate not to open the scoring when he headed inches wide following a superb cross from England international Bertrand.
Koeman's men continued to push for an opener and Virgil van Dijk came close when he fired a free-kick from a dangerous position just over the crossbar.
Southampton eventually got the goal they deserved in the 43th minute when Mane capitalised on some poor goalkeeping from Speroni, the Senegalese lifting the ball over the goalkeeper's head after he failed to adequately deal with a cross from Tadic.
Palace nearly replied immediately through Gayle, with Forster thwarting the striker from close range with a quick reflex save.
Forster showed his class again on the hour mark, making a diving save to keep Palace youngster Sullay Kaikai's bouncing effort out.
The home supporters breathed a sigh of relief when Pelle doubled Southampton's lead minutes later with his 11th league goal of the season, heading past the helpless Speroni after a fine cross from Cuco Martina.
Alan Pardew's men never gave up, though, and Puncheon pulled one back in the 64th minute, finding the top corner with a well-taken strike from inside the box.
The away side's resurgence ended in the 75th minute when the referee awarded Southampton a penalty after Mariappa and Pape Souare sandwiched Mane, with Bertrand stepping up to make it 3-1.
Mane came close to adding a fourth on two occasions, but it was Davis who eventually added his name to the scoresheet after some good work from Pelle.