Liverpool - Everton defender Phil Jagielka delivered a major blow to Southampton's bid to qualify for the Champions League as his first-half goal secured a 1-0 win at Goodison Park on Saturday.
Ronald Koeman's side needed a victory on Merseyside to keep in touch with the Premier League's top four, but Jagielka's strike left sixth placed Saints trailing fourth placed Manchester City by eight points with just seven games to play.
Southampton's first defeat in four matches leaves them with a place in the Europa League their most likely route to continental competition next season.
For Everton, a third successive league win lifted them into the security of mid-table, with a 12-point gap to the bottom three, after they briefly looked in danger of being dragged into the relegation dogfight.
It was an upbeat end to a day with started with the news that Everton midfielder Darron Gibson is likely to miss the remainder of the season after breaking a metatarsal.
The Republic of Ireland international was replaced by Gareth Barry, returning from suspension, with the other change seeing Ross Barkley replace Romelu Lukaku, who had not recovered from the hamstring problem which saw him miss Belgium's recent internationals.
Southampton were quickly into their stride and threatened in the first minute when defender Jose Fonte headed wide from a free-kick.
Graziano Pelle had scored just once in his last 16 appearances for Southampton, but the striker found the net in Italy's midweek friendly draw against England.
He came close to building on that morale-boosting goal when he met Shane Long's cross with a lobbed volley that Everton goalkeeper Tim Howard brilliantly clawed away from under the crossbar.
But failure to convert those early opportunities proved costly for Southampton as the hosts took the lead in the 16th minute.
A Leighton Baines corner was only half-cleared to Barry and his cross reached England international Jagielka, who steered a low shot into the corner for his fifth club goal of the season.
James Ward-Prowse nearly produced an immediate response from the visitors when the midfielder's curling free-kick found the side-netting with Howard beaten.
Ward-Prowse was proving a real menace to the Everton defence and another stinging strike drew a fine save from Howard.
Everton were back on the offensive when Aaron Lennon found Arouna Kone on the right and his cross reached Osman, whose header deflected just wide.
Koeman's team dominated possession in the second half but lacked the cutting edge to prise open Everton's back four in a lacklustre finale.