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.
Image caption, Marc Cucurella's goal was his seventh of the season in all competitions
Amorim goes strong but Man Utd beaten again
The only way Manchester United can salvage anything from a hugely disappointing season is by winning the Europa League, which brings with it the reward of a Champions League place.
With that in mind, it was surprising that Amorim opted to name a strong side for this game.
Amorim said before kick-off that he wanted his players to be feeling in a competitive frame of mind rather than rested before their trip to Bilbao.
While they stayed in this game, United's performance is unlikely to have inspired a great amount of confidence in the ranks before they face fellow Premier League also-rans Spurs in Spain.
They did not manage a permissible shot on target in the first half and only really threatened when Amad Diallo forced a decent save out of Robert Sanchez late on.
United are on their longest winless run in the Premier League, having failed to claim a victory in their last eight league matches.
But their performances in Europe have been better than on the domestic front.
They might muster some heart from that, as well as the news that Tottenham also head into the Europa League final on the back of a loss, having been beaten by Aston Villa.
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