Jason Kenny had to settle for sprint silver at the Track Cycling World Championships after a semi-final victory over Sir Chris Hoy which could have significant implications over selection for the London Olympic Games.
Kenny gambled in the second match of the best-of-three final with Gregory Bauge of France, accelerating from the start, and won the dash to the line.
However, the 24-year-old Olympic silver medallist from Bolton was relegated by officials for straying outside the sprinters' lane on the final bend, handing Bauge a third sprint world title with a 2-0 success.
Four-time Olympic champion Hoy, who was beaten 2-0 by team-mate Kenny in the last four, raced Australia's Shane Perkins for bronze and claimed a 2-0 success.
The sprint final was a repeat of the 2011 race for gold, which was belatedly awarded to Kenny after 2009 and 2010 champion Bauge was stripped of the title due to an anti-doping offence.
Bauge appears the biggest barrier to a successful British defence of the sprint title Hoy won in Beijing in 2008.
Kenny and Hoy are in a battle for an Olympic berth in the event.
Just one of the duo who finished first and second in the 2008 Olympics can represent Britain at the London Games under the one rider or team per nation per event rule.
Prior to the World Championships the room-mates each indicated their belief that Melbourne would have a significant bearing on Olympic selection and Kenny won the best-of-three contest 2-0 to advance to the final.
It means the selectors have a decision to make and Hoy may yet be denied the chance to defend his Olympic crown.