Chelsea gave their hopes of playing Champions League football next season a huge boost as Marc Cucurella’s second-half header saw off Manchester United at Stamford Bridge.
It was Cucurella’s seventh goal of the season in all competitions.
The Blues needed to win to ensure a top-five finish was in their own hands, but for a large part of Friday’s game they were frustrated by the visitors.
However, The Spanish International headed in Reece James’ excellent cross to secure a win that moves Chelsea up to fourth place in the Premier League.
They sit above Aston Villa on goal difference and a point clear of sixth-placed Manchester City, who have a game in hand.
Although his team have a crucial game against Tottenham in the Europa League final on Wednesday, United boss Ruben Amorim named a strong side for this trip to west London.
It looked like the decision would pay off when Harry Maguire fired home an excellent volley in the first half, but it was ruled out for offside after a review by the video assistant referee (VAR).
Chelsea’s James then hit the left post with a swirling effort before the break, and the Blues thought they had a penalty in the second half when Tyrique George went down inside the box as Andre Onana rushed out to push away the ball.
A spot-kick was given initially but then ruled out after a VAR check as replays showed Onana got the ball first.
But the home fans were celebrating soon after when James expertly curled a delivery to the far post from the right and Cucurella rose to guide a header beyond Onana.
Chelsea will travel to Nottingham Forest on the final day of the season knowing they can guarantee Champions League football in 2025-26 with a win.
Defeat for Amorim’s United, meanwhile, was their 18th in 37 Premier League games and leaves them 16th in the table.
Chelsea started this season so strongly that they were at one point being talked about as title contenders, but poor form around the turn of the year meant even securing European football for next term was looking uncertain.
But the Blues rediscovered their form just at the right time as three successive wins towards the end of April reignited their bid for a Champions League spot.
A 2-0 loss to fellow top-five hopefuls Newcastle last time out meant it was important they finished their home campaign with a victory to ensure their European destiny remained in their own hands.
It was not easy, as a striker crisis brought on by injuries and suspensions meant academy graduate George led the line for the Blues against United.
For a long while that lack of an experienced forward threatened to leave the Uefa Conference League finalists frustrated as they struggled to trouble Onana.
But ultimately Chelsea looked like the team with the greater desire for the win, and after Cucurella headed in they defended well to make sure of a potentially priceless three points.