Victoria Pendleton won the world championship sprint title for the fifth time after beating China's Shuang Guo in the final.
The 29-year-old had qualified only seventh fastest on Friday but she was in great match-winning form when it came to her semi-final against Anna Meares.
Meares, who has won the 500-metre time trial and team sprint for Australia this week, looked a dangerous opponent but Pendleton won their semi-final 2-0. It wasn't easy for Pendleton but she always looked in control.
China's Shuang Guo knocked out Simona Krupeckaite of Lithuania in the other semi-final.
In the final, Pendleton won the first race well. In the second, she fell as she rolled up a steep section of the banking shortly after the start, meaning they had to start again. Undeterred, Pendleton held off a spirited run by Guo to clinch Britain's second gold medal of the championships.
For Pendleton it was a fourth consecutive sprint title, a run that stretches back to Palma de Majorca in 2007, and the eighth rainbow jersey of her career.
Lizzie Armitstead won silver for Great Britain in the women's omnium behind Canada's Tara Whitten. The pair went into the last of the five events, the 500-metre time trial, tied on 20 points, knowing that whoever did best would win the rainbow jersey. Whitten finished third, with Armitstead ninth. Neither rider won one of the events, proving that the omnium is all about consistency. Whitten was second in the 200-metre sprint, third in the pursuit and 500-metre, sixth in the points race and ninth in the scratch race. Armitstead was strong in the bunch races - second in the scratch, third in the scratch, in the points and third in the scratch but ninth places in the pursuit and the 500-metres hit her gold medal chances.
There will not be a British winner in the men's sprint on Sunday after Chris Hoy, Jason Kenny and Matt Crampton were all beaten in the quarter-finals.
There was something of an upset in the 1/8 final race between Hoy and Robert Forstemann. The German received a hefty push off by his coach and, using a slightly lower gear to enable him to attack, he hit Hoy right from the start. It caught the Olympic champion by surprise and Forstemann was soon streaking ahead. The gap was huge and it took a massive effort from Hoy to get himself back into contention.
Forstemann was tiring on the final lap but he managed to get over the line first, although it was incredibly close. Some observers wondered why Hoy bothered to chase, knowing he'd have a better chance in the repechage with fresh legs, but it says everything about his competitive spirit that he fought with everything he had all the way to the line.
Hoy and Matt Crampton each won their repechage races to reach the quarter-finals, where they were joined by Jason Kenny, who had beaten Azizulhasni Awang of Malaysia at the first attempt.
In the last eight, Kenny lost in straight races to Kevin Sireau of France. Hoy won his first clash with another Frenchman, Gregory Bauge. However, Bauge hit back in style and won the deciding race in a photo finish. Crampton lost 2-1 to Forstemann. In the race for fifth to eighth places, Crampton beat Hoy, Pervis and Kenny.
The semi-final line-up on Sunday pits Bauge against Sireau and Forstemann against Australia's Shane Perkins.
Australia claimed their sixth gold medal of the week - and Cameron Meyer his third - when they won the men's Madison.
The French and Belgian teams gained a lap, but without scoring points, while the Aussie duo of Leigh Howard and Meyer notched up points. That meant the Aussies claimed the lead when they struck out to gain a lap towards the end of the race.
The 22-year-old Meyer has been the star of the championships so far, winning the points race and Madison as well as the team pursuit.
Sunday sees the final day's action of this year's championships. Ed Clancy will contest the men's omnium, Pendleton and Jessica Varnish are in the Keirin and there are also the latter stages of the men's sprint and the women's points race. Armitstead will make a decision on Saturday night whether to ride in that.
WORLD TRACK CHAMPIONSHIPS 2010 BRIEF RESULTS
Day four, Copenhagen
Men's Madison
1 Australia (Leigh Howard, Cameron Meyer)
2 France (Morgan Kneisky, Christophe Riblon)
3 Belgium (Ingmar De Poortere, Steve Schets)
Women's sprint
1 Victoria Pendleton (Great Britain)
2 Shuang Guo (China)
3 Simona Krupeckaite (Lithuania)
Women's omnium
1 Tara Whitten (Canada)
2 Lizzie Armistead (Great Britain)
3 Leire Olaberria (Spain)
MEDAL TABLE
1 Australia 6 gold 2 bronze
2 Great Britain 2 gold, 4 silver, 1 bronze
3 USA 2 gold
4 France 1 gold, 3 silver, 1 bronze
5 Netherlands 1 gold 1 silver
6 Germany 1 gold, 1 bronze
7 Canada 1 gold
8 Denmark 1 gold
Has cycling's most affordable pro bike brand just launched its aero machine?
Even if you ride a lot, here's why you shouldn't skip leg day at the gym
