Jason Kenny bid farewell to the Olympic men's sprint title he has held since London 2012 as he was beaten in the quarter-finals by Harrie Lavreysen at the Izu velodrome.
Kenny had earlier needed a repechage to get beyond the 1/8 finals after being beaten by Denis Dmitriev, but lived to fight another day as he saw off Azizulhasni Awang and Yuto Wakimoto – two riders he had already beaten in Wednesday's round.
But it was only a temporary reprieve as the 33-year-old, now Britain's most decorated Olympian after Tuesday's team sprint silver, was beaten in the first two races of the best-of-three quarter-final round.
On Wednesday the six-time Olympic champion had admitted he was struggling to recover from the exertions of the team sprint competition, and sounded like a man who knew he was about to hand over his crown.
Instead he called team-mate Jack Carlin Britain's best chance of getting a medal in the event, and the Scot duly advanced to the semis as he beat Germany's Maximilian Levy 2-0.
Katy Marchant's hopes in the women's keirin were ended in cruel fashion as she was caught in a crash through no fault of her own in the quarter-finals.
Marchant, who looked strong in Wednesday's opening races despite suffering one relegation, was taken out when Dutch rider Lauren Van Riessen appeared to clip a wheel in front and swung up the bank to take Marchant out of the race.
The Dutch rider received treatment at the track side before being taken away on a stretcher.
Marchant got back on her bike to finish the race but already knew she could not advance, with only the top four going through and no second chances at this stage of the competition.
"My legs felt good, I felt I was coming at the right time. But I was in the wrong place at the wrong time I guess. That's bike racing.
"I'm not really sure what happened. I was so focused on moving forward. I'm not sure if she clipped somebody's wheel at the side or she fell but her wheels took out mine."
The 28-year-old must now refocus ahead of the individual sprint, in which she took bronze in Rio five years ago, with the competition due to start on Friday.
"I think I'm alright," she said when asked if there was any lasting damage. "There's a bit of blood but I think I'm alright."
