Becky James took silver for Great Britain in the women’s keirin with a late surge down the back straight.
Elis Ligtlee of the Netherlands led from the front to win gold, with Australian Anna Meares in third.
James, 24, missed the London Games and then had the best part of 18 months out with a knee injury and a cancer scare.
She was last with one lap to go but found a way around the outside to force her way into second on the line to win Britain’s fourth medal on the track.
It was a second medal in two Olympic kierins for GB after Victoria Pendleton won the event in London – where it made its debut.
The silver medal came just minutes after Laura Trott became the first British woman to win three gold medals as she won team pursuit gold with Joanna Rowsell-Shand, Elinor Barker and Katie Archibald in a new world record time.
James told BBC One: “I can’t believe it happened.
“I came in with good form and I love the keirin and I love racing. Once I got through the first round I just wanted to enjoy the day. I was at the back and was just thinking ‘when do I go, when do I go?’
“It was so special, I have 10 of my family here – my mum has never been on a long-haul flight before.
“I have had so much support from British Cycling, it has been a tough two years and I couldn’t have done it without everyone’s help.”
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