Hayden Hackney's first-half finish was enough to give Middlesbrough a 1-0 win over Chelsea in the first leg of their Carabao Cup semi-final clash.
The midfielder has attracted attention from the likes of Tottenham and Manchester United and did any hopes of a summer move no harm, as he got on the end of Isaiah Jones' cut-back to put the Championship side in front at the Riverside.
That came after Cole Palmer had wasted a huge chance to give the Blues the lead, having pounced on a poor pass from Jonny Howson. It left Palmer with only goalkeeper Tom Glover to beat, but he could not even hit the target.
The Chelsea star, so impressive for much of this season, had a chance to make up for that in first-half stoppage with an equaliser, but produced an even worse miss, somehow sending the ball over the bar from a couple of yards out after Enzo Fernandez's shot had been spilled into his path.
Palmer had a third big opportunity seconds later, cutting inside onto his left foot inside the box, and did at least test Glover this time, but it was a routine save.
Chelsea, as expected, saw plenty of the ball after the break, but Middlesbrough were largely untroubled, as Raheem Sterling and Mykhailo Mudryk failed to make the most of openings from the edge of the area.
The hosts dropped deeper in the closing stages, but a sustained charge from Chelsea never materialised, leaving the Blues with work to do at Stamford Bridge in the second leg in two weeks' time if they are to take their place at Wembley in the Carabao Cup final next month.
