Jon Dibben won Britain's second gold of the Track World Championships with a superb ride in the men's points race.
Dibben, 22, won the final two sprints to reach 48 points - the same score as Andreas Graff - but crossed the finish line of the 160-lap race first.
Earlier, Andy Tennant edged out fellow Briton Owain Doull by 0.175 seconds to win bronze in the men's pursuit.
Laura Trott, who won GB's first gold medal on Thursday, helped the hosts win another bronze in the team pursuit.
But it was the talented Dibben who stirred the 8,000 crowd into a thunderous roar as he attacked on the final sprint to win a four-man battle for gold.
"I'm lost for words," Dibben told BBC Sport. "I came into this to give it my all. I rode it like an omnium points race. For 100 laps I was at my limit and in the last 20 everyone else just died off."
So impressive was the Team Wiggins rider's performance, the European omnium bronze medallist has given the British selectors an Olympic dilemma.
|Analysis - Olympic champion Chris Boardman|
|"It was an incredible ride. If he can tighten up his tactics, he will be a force in years to come. That's going to put him in contention for the omnium as well."|
Cavendish or Dibben?
The celebrated Mark Cavendish finished on 84 points after three events in the omnium, an excellent performance in the elimination race on Friday night boosting his chances of a medal.
British Cycling technical director Shane Sutton has said the Manxman has to finish in the top three to secure his spot for Rio.
Even if the 30-year-old achieves that aim in London, the selectors face a conundrum as Cavendish's inclusion in the omnium would mean having to select him as part of the five-man team pursuit, and his coach Heinko Salzwedel has admitted the rider has a "long way to go" to reach the required standard.
His main rival for a place in the team is Dibben, who is currently the stronger of the two in the team pursuit and is a classy omnium operator.
"That's going to put him right back in contention for the omnium," said Boardman. "I wouldn't want to be a selector with Cavendish doing so well in the omnium."
Cavendish in contention
But Cavendish, who is hoping to balance his road commitments with his quest for a first Olympic gold, is well placed with the kilo, flying lap and points race remaining on Saturday.
In the day's two other events, he finished sixth in the 15km scratch and 13th in the pursuit, his weakest event.
Boardman said the Briton rode a "fantastic" strategic race in the elimination.
Six-time Olympic champion Sir Chris Hoy added: "He's been off the track for a while but you could see his brilliance coming back at the end. He can't afford to have a bad event now. He has to be consistent. The points event is a good race for him - he's got to make sure he's not outside the top three or four in each event."
Women's pursuit team make a statement
Britain's quartet of Trott, Elinor Barker, Ciara Horne and Joanna Rowsell Shand put Thursday's disappointing qualifying display behind them with two superb rides on Friday.
They broke the British record with a time of four minutes 16.350 seconds to qualify for the bronze medal race and went on to beat rivals New Zealand by nearly four seconds to secure third place in 4:16.540.
Trott, the women's scratch world champion, said the team wanted to "prove people wrong" after a ragged ride on Thursday.
"We were disappointed at how we rode and to come back fighting and post 4:16 in two races was better than we thought we were going to do," said the double Olympic champion.
Trott, who could end these championships with a hat-trick of medals as she competes in the gruelling six-event omnium over the final two days, said Friday's performances had given her momentum.
In the last competition before the Olympics, this week's team pursuit offered a glimpse at how closely contested the event will be in Rio with the United States going close to breaking the world record in the semi-finals and dipping below 4:17 to win gold in the final.
Britons battle for bronze
Team-mates Tennant and Doull produced a sensational finish with just a 10th of a second separating the pair as Tennant won in 4:18.301.
Welshman Doull, 22, hauled himself back into contention in the closing stages, but was pipped by his fellow Team Wiggins rider.
"That's the icing on the cake for me," said 28-year-old Tennant. "To come away with individual bronze medal - if you'd asked me three weeks ago, I'd have been betting against myself."
Italy's Filippo Ganna (4:16.141) secured gold, beating Germany's Domenic Weinstein (4:18.275) in the final.
Kenny makes strong start
Olympic champion Jason Kenny qualified in second place as he made a strong start to the individual sprint competition.
The 27-year-old has endured a lean few years since winning two gold medals at the London 2012 Games but showed promising signs by advancing serenely to the quarter-finals.
Team-mate Callum Skinner joined him there by beating defending champion Gregory Bauge.
Kenny was just 0.001secs behind fastest qualifier Matthew Glaetzer of Australia while Skinner was fifth fastest in 9.824.