Victoria Pendleton picked herself off the floor to record a brilliant semi-final victory over Australia's Anna Meares en route to world sprint gold.
Pendleton suffered track burns after a crash in her first best-of-three semi-final heat against arch-rival Meares.
The Briton struck back to reach the final in Melbourne, where officials relegated Lithuania's Simona Krupeckaite to hand her gold.
"It's been an emotional rollercoaster," Pendleton told BBC Sport.
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Pendleton on 'rollercoaster' day
"That's not necessarily the way I'd like to win, in an ideal scenario, with relegations and stuff. It always feels a bit weird and not very true to the sport, but those are the rules.
"I'm delighted with the result. I didn't think it was going to happen coming into today. It's great to end on a high."
Pendleton intends to retire after the London Olympics and will now do so with nine career world titles to her name, including six in the sprint.
To keep her hopes of winning this one alive, she first had to peel her battered right side up from the Hisense Arena track. She clashed arms with Meares in the midst of a frantic finish to their first semi-final heat, sending the 31-year-old crashing down and burning her right shoulder, elbow and hip on the wooden surface.
"It's not too bad. I lost my balance, went too far in one direction and lost my traction," she said.
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Pendleton wins thrilling semi after crash
"My dad always said you don't do track cycling unless you're prepared to crash. I slid quite nicely, which sounds random, and I felt fine. I could tell it was just surface wounds."
Olympic champion Pendleton against world champion Meares is the London 2012 sprint final to which track cycling fans and the media have been eagerly building ever since Beijing 2008, where they finished first and second respectively.
If the Australian has recently appeared out of Pendleton's league on one or two occasions, the latter laid her body on the line to prove more than Meares' match in Melbourne.
Officials relegated Meares from the second heat for straying outside her racing line, levelling the score at 1-1.
Pendleton - burns showing through large holes in her GB skinsuit - then upstaged the 28-year-old Meares in a spectacular deciding heat, winning in a photo finish.
The final against Krupeckaite, last year's silver medallist, felt predestined for Pendleton in front of a muted Australian crowd.
But the victory came in odd circumstances. Pendleton won heat one and Krupeckaite seemed to have levelled in the second race before the Lithuanian, too, was relegated in identical circumstances to Meares.
Pendleton, already off the track and preparing for a deciding heat when the relegation and her consequent victory were announced, fell into an emotional celebration as she won Britain a third gold medal of the week in Olympic events (fourth overall). Meares took the bronze.
"I was disappointed with the team sprint [on Wednesday, when Pendleton and Jess Varnish failed to earn a medal]," said Pendleton.
"It left me flat, I must admit. Picking myself up
