British number one Dan Evans saw his bid to reach the Wimbledon last 16 for the first time ended by American prodigy Sebastian Korda.
Evans, 31, had not dropped a set in his opening two matches, but the 22nd seed came unstuck against 20-year-old Korda.
Wimbledon debutant Korda, ranked 50th in the world, looked unfazed on the big stage as he won 6-3 3-6 6-3 6-4.
Two-time champion Andy Murray will hope to soften the blow for the home fans when he follows on Centre Court.
The former world number one takes on Canadian 10th seed Denis Shapovalov, aiming to become the first British man to reach the second week of this year's tournament.
That honour could have fallen to Evans, only for the world number 26 to lose against a 20-year-old considered one of the rising stars of the sport.
Korda, son of former Australian Open champion Petr, played with clarity and confidence throughout most of the match.
The tall right-hander demonstrated his all-round ability in front of the 7,500 fans, forcing mistakes from Evans with his powerful forehand and showing a willingness to go to the net.
"He's got the game, the belief, the composure - he's got it all, actually. Things can only get better," former Wimbledon champion John McEnroe said in his role as a BBC television analyst.
By contrast, Evans was restless throughout and regularly shouted towards his box as he was unable to find a way around Korda.
His frustration peaked when he failed to consolidate a break for a 5-2 lead in the fourth set, before a double fault effectively destroyed his chances when it helped put Korda 5-4 up.
Korda, though, still had to keep his nerve and serve out. He missed a smash for 0-30 to give Evans - and the crowd - hope, but responded with a service winner and backhand down the line to level.
A 123mph ace down the middle teed up a first match point, which he calmly took with another smash.
Korda raised both hands in the air as he looked towards his father, who was watching on, as a despondent Evans quickly left court.
Korda will now look forward to playing his first Wimbledon last-16 match on his 21st birthday, when he faces Russian 25th seed Karen Khachanov on Monday.