Chelsea 3 Leeds United 2: Mateo Joseph's two goals ensure Whites leave the FA Cup in better health than they came into it

But as the teenager, watched by his great-uncle Eddie, sashayed the ball around in midfield like he owned it and hunted it down when he did not have it, another Leeds youngster made a name for himself.

Those who work at Leeds have known for a long time Gray was going to be a star, and that Mateo Jospeh was bursting with talent but the 20-year-old’s first two goals for the club showed he has the temperament to transfer it to the big stage and that, as any Stamford Bridge season-ticket-holders will tell you once their eyes stop rolling, is not a given.

Cheslea's ability – and one of the substitutes who really should have started the game – got them through to the quarter-finals by the skin of their teeth, Conor Gallagher scoring a 90th-minute goal that underlined the England international's quality but it was Joseph who was the individual winner of a night where Leeds – with not so much bigger fish to fry as a blue whale – could not really lose despite what the 3-2 scoreline might tell you.

Joseph might even have scored a hat-trick, failing to get a clean header n Dan James' 73rd-minute cross. He had more than earned some slack by then, though.

As he was stealing the headlines, Joel Piroe, signed as a guaranteed Championship goalscorer who lived up to his billing in the first part of the season, sneaked off when Leeds chased victory after another ineffective performance.

With five changes, like Leeds, Chelsea's team-sheet did not scream of desperation to save their disappointing season but as well they might after all the money Todd Boehly has spent on their squad, they still have plenty of quality in reserve.

Even so, there is sloppiness about them which has held them back at times this season, and Leeds were quickly able to exploit it.

James had already got on the end of a long ball without being able to direct it off balance when Joseph scored his first senior goal for Leeds after just 10 minutes.

It came from one of those trying-to-be-too-clever goalkicks which Chelsea never managed to get out of their penalty area, Gray – his midfield partnership with Ethan Ampadu restored after long spells for both in the back four pressured Axel Disai into giving up the ball and Jaidon Anthony quickly gave it to the 20-year-old.

But when Chelsea are switched on, they do have quality no Championship side can match.

They quickly came to dominate the possession statistics, and cut Leeds open with a couple of quality moves.

The first came in the 16th minute, Noni Madueke laying the ball back for Moises Caicedo to play a lovely pass to Nicholas Jackson. The centre-forward slipped the ball through the legs of Illan Meslier

Meslier saved a long-ranger from Enzo Fernandez, who had already shot wide with a pot-shot but it was when Chelsea tried to work the ball closer to him that they were at their most dangerous.

When Meslier had to stick out a foot to deny Mykkhalio Mudryk it was Liam Cooper's header, rather than any blue brilliance, which gave him the chance from a tight angle.

Madueke shot into the side netting after bursting onto the ball when Leeds failed to properly get a corner clear.

Ukrainian Mudryk is much derided – he certainly was by the 5,000-plus away fans when he took a conrer in front of them – but as his eye-watering transfer fee would suggest, he can play a bit.

His 37th-minute finish was as good as its creation, Madueke coming inside and spreading the ball to Malo Gusto. He found Raheem Sterling, whose low ball in was just behind Mudryk, but not enough to stop him drilling in.

There was no need for Leeds to give up heart in the quest for a home quarter-final – a ludicrously-timed draw meant both sides found out shortly before kick-off they would be hosting Leicester City if they won.

James was unable to stop himself ballooning the ball when Junior Firpo hit what looked like a shot into the turf and it bounced up at the winger, then Anthony curled a shot just wide having beaten Gusto to the ball, then taken it past him.

But Leeds took a grip of the game a the restart and did not let go of it until the desperation minutes at the end of the game – despite Chelsea gradually throwing on the players who ought to have started in the first place.

It was no less than they deserved when, with the hour approaching, Ampadu looped a ball out to the lively Anthony who got a yard's crossing space and used it to good effect to pick out Joseph to head an equaliser.

Leeds' confidence was started to shine through, as shone by a couple of Gray dribbles deep enough to require a bit of coverage and even Meslier dropping the shoulder to Jackson. Ole.

Leeds' top priority had to be Saturday's West Yorkshire derby at Huddersfield Town, but they still wanted to win badly enough to throw Crysencio Summerville and Willy Gnonto on from the bench.

An Anthony effort had the sting taken out of it by a deflection and the next curled wide after beating Trevoh Chalobah, one of two former Huddersfield loanees now in the home team's back four.

Eventually, Chelsea's big players came to the party, World Cup winner (and young player of the tournament) Fernandez picking the ball up near the halfway line, carrying it, then playing a pass perfectly weighted for Gallagher to find the net.

With Meslier up for the last play of the game – it was Gray trusted to be the one-man defence – Liam Cooper missed his header at the corner.

Leeds are out of the FA Cup Joseph's performance means they leave it stronger than they went in.

Chelsea: Sanchez; Gusto (Chilwell 61), Disasi, Chalobah, Gilchrist (Colwill 74); Fernandez, Caicedo; Mudryk (Tauriainen 90+3), Sterling (Palmer 74), Madueke (Gallagher 61); Jackson.

Unused substitutes: Petrovic, Murray-Campbell, Samuels-Smith, Harrison.

Leeds United: Meslier; Roberts, Rodon, Cooper, Firpo; Ampadu, Gray; James (Gnonto 78), Piroe (Summerville 78), Anthony; Joseph.

Unused substitutes: Klaesson, Van den Heuvel, Cresswell, Bamford, Kamara, Byram, Shackleton.

Referee: D Coote (Nottinghamshire).