Perkins beat the Briton, who had had to settle for bronze in the previous day's sprint, in the event which is likely to be his strongest at London 2012.

Sir Chris, who had won the world keirin title the last three times he had competed, said the competition had taken its toll.

"It's not the physical side, it's the emotional and mental side, getting yourself up after you've lost a race and fighting back," he said.

"It's energy sapping, it really does take it out of you.

"I'm emotionally and physically exhausted right now.

"I'm looking forward to a couple of weeks off the bike and then I'll get back in the gym and start the season again for next year."

Australia had earned another prestige win over Britain earlier in the day when Anna Meares had prevented Victoria Pendleton from winning her fifth consecutive sprint title, beating her 2-1 in a cagey semi-final before beating Simona Krupeckaite of Lithuania in the final.

Pendleton had to settle for bronze after beating Olga Panarina of Belarus.

The 30-year-old Briton, who beat Meares in the 2008 Olympic final, recovered from an early defeat to level at 1-1 after producing an explosive finish in the second semi-final heat, coming around the outside of Meares on the final straight and forcing the Australian into a decider.

But then Meares adopted her typical cat-and-mouse crawl before the sprint, edging up to the fence and unnerving Pendleton, who was unable to make up enough ground before the 27-year-old crossed the finish line.


"I was surprised I got the opportunity to put Vicky there," Meares stated.

"She doesn't often allow that to happen.

"I took the chance, I took the risk and it paid off.

"To be able to beat her is a big honour for me.

"We have a big rivalry, but I admire her for the rider that she is."

Pendleton was seeking her sixth world title in seven years.

"I'm not in the best form but I'm working on a two-year plan," the Olympic sprint champion said.

"You have got to have confidence and patience in your form and stick to your plan.

"I've been in every semi-final since 2003, so I don't think that's a bad run.

"Anna Meares is in the form of her life and I'm not but don't write me off yet."

Britain's 20-year-old Dani King won bronze in the non-Olympic scratch event, adding to her team pursuit world title from Thursday (March 24).

Laura Trott, her 18-year-old team mate in that victory, had a more difficult day after an early exit in the elimination race contributed to her finishing 18th after half of the omnium events, for which she was selected at short notice following an injury to Lizzie Armitstead.

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