Riders from the Netherlands and Great Britain won gold, and Jason Kenny's quest for a ninth Olympic medal will have to wait after a defeat in the men's sprint knockout rounds Thursday on a long day of cycling at the Izu Velodrome.

Men's omnium: European champion Matt Walls of Great Britain finished in the top three of the first three races of the four-race event and earned points early in the event-closing race to take the gold medal.

Walls started with a win in the scratch race, a straight-up head-to-head mass start race, ahead of France's Benjamin Thomas and the Netherlands' Jan van Schip. The order of the top three was reversed in the second phase, the tempo race, to create a three-way tie for the lead. Defending champion Elia Viviani of Italy won the elimination race to pull into contention, with Walls placing second to move into the lead. 

In the points race, Walls took firmer control, racking up 20 points for joining a breakaway that lapped other riders and winning some sprint points along the way. New Zealand's Campbell Stewart got into two field-lapping breakaways and vaulted up the standings to take silver, while Viviani took the most sprint points to win bronze. American Gavin Hoover improved his standing by getting into a breakaway for 20 points on the way to an eighth-place finish. (RESULTS)

Women's keirin: Two Ukrainians and two Canadians rode in the six-rider final of the event in which a pacer pulls the pack up to a set speed before unleashing the cyclists for a final sprint, but if either country's cyclists were trying to work together, it didn't work. The Netherlands' Shanne Braspennincx broke ahead on the last lap and stayed just ahead of New Zealand's Ellesse Andrews at the finish. Canada's Lauriane Genest took bronze. (RESULTS)

Men's sprint: Kenny is out, but Jack Carlin ensured a British presence in the final with a win in the quarterfinals. Denis Dmitriev got a second chance when race officials ruled that Trinidad and Tobago's Nicholas Paul had committed an infraction in the second of their best-of-three series, and the Russian made the most of it with a convincing win in the final race between the two. Harrie Lavreysen eliminated Kenny to make the semifinal alongside fellow Dutch rider Jeffrey Hoogland. (RESULTS)