Britain's Jason Kenny took silver in the men's sprint as Frenchman Gregory Bauge successfully defended his World Championships title.
Kenny, 23, reached the final with a 2-0 semi-final victory over Sir Chris Hoy but Kenny was no match for the brilliant Bauge in the final.
"It's a shame to finish on a loss but I'm really pleased with a silver medal," Kenny told BBC Sport.
Hoy salvaged some pride with a bronze medal, defeating Mickael Bourgain 2-1.
Hoy had to come from behind to beat the Frenchman in the best of three race, which brings Britain's haul to six medals at the penultimate World Championships before London 2012.
Tired Kenny thrilled with silver
Britain now have one gold, two silvers and three bronze medals from three days of competition, with two days remaining.
While Kenny was delighted that he made the final, he admitted that Hoy had already pushed him to the limit.
"Riding against Chris really took it out of me with two really, really hard rides," said Kenny. "Bauge had too much pace at the end of the day and I didn't seem to have an answer for it.
"Chris and I train together, we started doing a lot of efforts together in training so it all feels very familiar when we're racing."
Only one Olympic sprint place is allocated to each country and, although Kenny will draw confidence from his win over Hoy, he is not about to get carried away.
"Selection as usual will be done at the last second to ensure we get the best team," said Kenny. "At the minute there are four or five us realistically in the mix and it could be any one of us. I'm concentrating on being fastest for now and picking up any results I can on the way."
In the women's competition, Britain's Victoria Pendleton progressed to the best-of-three semi-finals, but her team-mates Becky James and Jessica Varnish were eliminated in the second-round repechage.
Pendleton is seeking a fifth consecutive world title in the event and a sixth in seven years.
Britain's Sam Harrison, the replacement for Ed Clancy who had to withdraw from the event through illness, lies 10th at the halfway stage of the omnium.
Hoy vows to bounce back after bronze
Harrison, 18, finished 6th in the flying lap, 19th in the 30km points race and 7th in the elimination race with the final three races, the 4km individual pursuit, 15km scratch race and 1km time trial, to come on Saturday.
In the evening's other races, Colombia's Avila Vanegas Edwin Alcibiades won the men's 40km points race, a 160-lap race with 16 intermediate sprints, with Australia's defending world champion Cameron Meyer in second.
Sarah Hammer of the United States won her fourth world title in the women's 3,000m individual pursuit, beating New Zealand's Alison Shanks.
Shanks led for all but the last 500m of the race when Hammer showed strength to come through and win. Lithuania's Vilija Sereikaite beat Jamie Nielsen of New Zealand convincingly to win bronze.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.