Mark Cavendish’s Olympic hopes are in the balance, with the Briton sitting seventh in the omnium at the Track Cycling World Championships in London.
He was 12th in the kilo, the fourth of six events, and is 38 points behind leader Fernando Gaviria.
Cavendish clocked one minute 04.507 seconds to move to 102 points.
Britain’s double Olympic champion Laura Trott finished third in the women’s omnium scratch race, the first of her six events at the Lee Valley VeloPark.
Trott, 23, has already won scratch gold and team pursuit bronze at these championships, and will be confident of adding to her tally as she is the Olympic champion in the omnium.
She will next compete in the 3km pursuit in Saturday’s afternoon session.
But Cavendish has work to do, with British Cycling technical director Shane Sutton having said the Manxman must finish in the top three to have a chance of competing in Rio this summer.
The omnium concludes on Saturday night with defending champion Gaviria leading on 140 points.
Elsewhere in Saturday’s morning session, Britain’s Jess Varnish and Katy Marchant failed to progress to the quarter-finals of the women’s sprint.
Meanwhile, Britain’s Lizzie Armitstead secured her second successive victory by capturing the Italian one-day classic Strade Bianche in Tuscany.
The race over gravel roads was the first instalment of the new women’s UCI WorldTour.
Armitstead, 27, began her season by winning the Omloop Het Nieuwsblad in Belgium last month.
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