Three-time Olympic champion Jason Kenny will return from the Track Cycling World Championships without stepping foot on the podium after his early elimination from the sprint as Great Britain were blanked on the penultimate day of competition.
The 25-year-old from Bolton had to settle for a hat-trick of fifth-place finishes after his quarter-final elimination in the sprint to France's Francois Pervis, who has won two gold medals already and is on course for another on Sunday's final day.
With Ed Clancy finishing fifth in the men's omnium, Britain's men have one final, and unlikely, opportunity to claim a medal at the championships, in the unpredictable Madison through Jon Dibben and Owain Doull.
Britain's women missed out on a medal on day four, with Jess Varnish and Katie Archibald fourth in the women's sprint and points race, respectively, but they have further medal hopes on Sunday.
Olympic champion Laura Trott is well placed at the halfway point of the omnium - second, but six points adrift of defending champion Sarah Hammer of the United States - and Varnish, 2013 gold medallist Becky James and Vicky Williamson go in the Keirin.
The laid-back Kenny was unable to reveal reasons for the poor performances of Britain's men. Clancy struggled to do so, too.
Asked if he could offer an explanation, Clancy, the senior squad member at 28, said: "No, in a word. This whole track campaign (the season) hasn't been a bad one. We've had some great results, great performances, just not this week.
"Truth be told this whole week's been a bit of a nightmare. Team pursuit, it started off there."
Clancy - part of the team pursuit squad which finished eighth on day one in the worst British result in the event in more than 15 years - won three of the six disciplines in the omnium, an event in which he won world gold in 2010 and Olympic bronze in 2012, but did not make the podium.
He won the flying lap on the first day and the final two events on the second, the scratch race and the one-kilometre time-trial, but his medal bid was undermined by an unusually poor four-kilometre individual pursuit, which saw him place 14th.
"With the form I had (fifth) is the best I could've hoped for," Clancy said.
"The pursuit I was going nowhere. Points and scratch and elimination race weren't that bad. It's the pursuit where we lost ground here today.
"Back to the drawing board and we'll try to sort it out next year."
Kenny's day was challenging from the moment he qualified in a lowly 14th place, giving him a difficult route to the knockout stages.
He lost to Germany's Stefan Botticher in the second round, falling into the repechage before advancing at the second attempt - team-mate Matt Crampton was eliminated - to face Pervis, who won their last-eight duel 2-0.
"It's fractions," Kenny said. "Unfortunately we're at the wrong end of those fractions. We want to be fractions in front instead of fractions behind.
"The three fifths tend to speak for themselves. I feel a little bit behind the top runners."
Varnish was fractions behind, too.
She beat team-mate and defending world champion Becky James on day three before suffering a 2-0 semi-final loss to China's Zhong Tianshi, who beat Olympic champion Anna Meares of Australia in the quarter-finals.
The 23-year-old from Bromsgrove met Lin Junhong of China in the battle for bronze, falling to another narrow 2-0 loss.
Kristina Vogel of Germany won gold with a 2-0 defeat of Zhong.
Varnish said: "It's disappointing not to be on the podium. I thought it was going to be doable today but it just wasn't there for me."
Archibald, team pursuit world champion on day two, put in a gutsy display in just her fourth international points race.
The 19-year-old from Milngavie, near Glasgow, was one of seven riders to gain a lap - and with it 20 points - on the field, but she was squeezed out of contention as Amy Cure of Australia won gold.
Archibald, making her World Championships debut this week, said: "Fourth is a positive for me, but it's a shame. You could argue it was close, but it wasn't close. I didn't have it."
Trott was trailing Hammer at the halfway stage of the omnium.
The American was second in the flying lap and won the points race and elimination race, usually Trott's domain.
The Briton was third in the first two disciplines and fourth in the elimination.