Great Britain were twice beaten by the Netherlands to gold on the opening day of the UCI Track World Championships in Santiago, Chile.
The Netherlands were defending champions in the men's team sprint events, and retained their rainbow jersey in that, while the women's team sprint final was a mirror image, as GB were edged out.
In the women's sprint, the Dutch team of Kimberly Kalee, Hetty van de Wouw and Steffie van der Peet beat the British trio, Emma Finucane, Iona Moir and Rhianna Parris-Smith, by three hundredths of a second. Australia beat Poland by two seconds in the bronze final to take third.
While Finucane was part of the three which won Olympic and world titles last year, she was joined by two debutants; it was Finucane's sixth world medal at 22.
"I'm so proud of these two," Finucane said. "It's their first world championships and to go out there in the gold medal ride-off, be composed, feel the pressure - we couldn't have asked for more."
Straight after, in the men's team sprint final, the Dutch team of Jeffery Hoogland, Harrie Lavreysen and Roy van den Berg beat the British trio of Matt Richardson, Joe Truman and Harry Ledingham-Horn by three hundredths of a second again. In a repeat of the women's event, Australia were third, beating France in the bronze final.
Lavreysen is now a 17-time world champion. The Dutch three were Olympic champions last summer, while this is a new lineup for GB at this level. Hoogland is an 11-time world champion, while Van den Berg has six rainbow jerseys.
"Coming away with a silver medal is bittersweet for me," Richardson said post-race. This is his first Worlds since switching his nation to GB from Australia.
"My first medal at a world championships in a GB skinsuit is going to feel amazing," he continued. I wish it was the top step, but I can't come away too mad about that.
"We're a fresh line-up, so each time we step on the track we're learning a little bit about each other."
Truman added: "It's the closest we've ever been to the Dutch and it's a really positive first step in the cycle [to LA 2028]."
The other final of the opening day was the women's scratch race, where Lorena Wiebes defended her title, out-sprinting Amalie Dideriksen (Denmmark) and Prudence Fowler (New Zealand).
In qualifying for the men's team pursuit, Denmark went fastest, and qualified for the first round alongside Australia, GB, New Zealand, the United States, Italy, Germany, and Switzerland.
In qualifying for the women's team pursuit, Italy qualified fastest, followed by GB, Germany, Australia, Belgium, Japan, Switzerland and Poland.
