The Canadian swimmer, who was part of the 4x200m freestyle relay team that finished fifth in Athens, went out partying in the city the night before the closing ceremony.

The evening took a violent turn when he was caught in the middle of a riot and ended up being punched and kicked by Greek police.

'I was having a drink with a few of the other athletes in one of the bars and a fight broke out right where I was standing,' he recounted yesterday.

'I had nothing to do with it but next thing I knew, there were riot police and I got beat up pretty bad.'

He had to skip the 2005 World Championships because of his injuries, and even had to see a psychologist to get over the mental trauma.

He suffered another setback in 2006 when he was diagnosed with asthma.

Incredibly, he bounced back to win at the World Championships in Melbourne last year.

He touched home first with Italian Filippo Magnini in the 100m free.

Australian sprint king Eamon Sullivan was relegated to second place.

At Beijing, the 24-year-old Canadian wants to win his first Olympic medal - and banish the demons from that fateful night in the Greek capital.

Said the freestyle specialist: 'I don't want that incident to be the defining moment of my career. Right now, I'm very motivated to do well.'

Hayden and the rest of Canada's 27-member swim team are in Singapore for two weeks to prepare for Beijing.

In Athens, the Canadians finished empty-handed in the pool - the first time in 40 years they failed to land an Olympic swimming medal. The shut-out was 'a good kick in the rear' for Canadian swimming, said Hayden.

The sport subsequently went through a facelift, with new coaches and a revamped talent-spotting programme.

Four years on, the country's hopes rest on the broad shoulders of Hayden, who will be swimming in the 100m and 200m freestyle.

But the 1.93m-tall Vancouver resident was cautious about making medal predictions.

'To be honest, I'm not thinking about the races right now,' he said. 'I'm just thinking about how I can be faster today than I was yesterday.'

Hayden will be up against the likes of Sullivan, French world record-holder Alain Bernard and American star Michael Phelps in the 100m.

He is also a member of the Canadian 4x100m and 4x200m freestyle relay teams and the 4x100m medley relay team, who are ranked second in the world.

The relay events, said national coach and Canada Swimming's chief executive Pierre Lafontaine, represent their best chance of a podium finish.

'We have a very good team and it is the relays that are very competitive,' said the former Australian Institute of Sport head coach. 'But we are really planning for the 2012 Games, where we will be a lot more competitive.'

For Hayden, though, redemption lies just around the corner in Beijing.

'In Athens, a lot of people were just happy to be there,' he said. 'There is much more desire to win this time round.

'I'll be disappointed if we don't come back with a medal.'

tvoon@sph.com.sg