Defending champions New Zealand beat the Netherlands to take gold in the men's team sprint at the world track championships on Wednesday, as Britain, who dominated the Rio boards at last year's Olympics, endured a disappointing day.
Russian duo Daria Shmeleva and Anastasiia Voinova also defended their title in the women's team sprint final, beating Australia's Kaarle McCulloch and Stephanie Morton, with Germany holding off China to take bronze.
Britain's Elinor Barker was pipped to gold by Italy's Rachele Barbieri, who overhauled the Welsh rider with metres to go in the 10km women's scratch race, while Jolien D'Hoore of Belgium finished third at the Hong Kong Velodrome.
"I went ever so slightly too soon and that probably cost me the race," the 22-year-old Barker told the BBC. "I was just not fast enough. Congratulations to her but I'm really disappointed."
Britain, who won six track golds in Rio, also suffered disappointment in the men's team sprint, with the young trio of Jack Carlin, Ryan Owens and Joseph Truman finishing third-fastest in qualifying but failing to get past runners-up Netherlands in the first round.
In the men's team pursuit, Britain's Andy Tennant, Mark Stewart, Ollie Wood and Chris Latham will go head-to-head with Italy in Thursday's race for the bronze medal, while Australia and New Zealand vie for gold.
Britain bagged gold medals in both the men's and women's team pursuit in Rio, but Australia's Sam Welsford, Cameron Meyer, Kelland O'Brien and Alexander Porter came within a whisker of breaking the world record set by the British men at the Olympics.
Australia qualified in 3:50.577, just outside the world record time of 3:50.265 that Ed Clancy, Owain Doull, Steven Burke and Bradley Wiggins managed last year.
Britain's new-look women's pursuit team of Eleanor Dickinson, Emily Kay, Manon Lloyd and Emily Nelson remain in the hunt for a bronze medal after finishing fifth in qualifying, and face Poland in the first round on Thursday.
(Reporting by Hardik Vyas in Bengaluru; Editing by Toby Davis)