In the women's field, Great Britain's Jodie Swallow shattered her opponents with a dominant display from the outset, leading out of the water and breaking well clear on the bike to eventually win by more than 11 minutes from Australia's Rebekah Keat.
The 29-year-old American executed a tactically astute race, exiting from the 3km swim in sixth place behind noted swimmers Cayton Fettell (AUS) and Kieran Doe (NZL). He and Great Britain's Paul Ambrose showed their class on the 80km bike leg to bridge the gap and while Ambrose attacked early on the 20km run, it was O'Donnell who held his form in 32 degree heat to beat off a determined challenge from Frenchman Sylvain Sudrie to win by more than a minute in a time of 3hr 48min 15sec. Denmark's Martin Jensen took bronze.
"Man, that swim was rough; I was happy to get out of the water," said O'Donnell. "The wind just threw up so much chop you could hardly see where you were going. But I just built into it on the ride and put myself in a good position behind a couple of guys I was confident I could pick up on the run. Sylvain (Sudrie) is a great runner so he was tough to drop out there but I think I put together a very sound race today."
Australia's Craig Alexander, who pulled out of the race earlier in the week, was on the money when he nominated O'Donnell as the man to beat. Alexander was the first to congratulate O'Donnell, whose consummate display signalled there may well be some mighty battles between the pair in the future. O'Donnell, however, is keen to compete at the London Olympics before contemplating a move to the Ironman format.
"Craig just said I deserved it and that I ran a smart race which is really nice coming from someone like him," commented O'Donnell. "He's the consummate professional, so meticulous and so talented. I look forward to racing him next year over in the US; I actually beat his race record in the St Croix 70.3 this year, so I'm sure he'd be keen to come back and put me in my place. At least this will give me a great confidence boost."
Shifting to the women, Swallow's display was simply outstanding. She had arrived in Perth ten days early and looked right at home from the outset, building on a small lead out of the water to make the most of her powerful frame on the bike and establish a lead of almost eight minutes off the bike. Reigning Australian Long Course champion Pip Taylor tried to stay in touch but suffered cramps, while Keat was unable to muster her usual challenge having competed in Kona only a fortnight ago. Swallow powered to the line unchallenged in a time of 4hr 7min 38 sec, with Keat second and Delphine Pelletier of France third.
"Everything came together really well for me out there so I couldn't be happier," Swallow said. "Before the race everyone seemed to be asking me if I could handle the travel and the hot weather but if you prepare well for these races you give yourself every possible chance. I went to the Olympics (in Athens) and that was a tough experience but you learn and you move on, so to come back and win a world championship is very pleasing. It was hot out there but I managed a pretty complete performance; I'm very proud of myself."
Keat dragged herself to the line in a gutsy display but it was a distant second.
"That really hurt; I'm totally spent," she said. "I tried to mount a challenge but Jodie was on another planet, so full credit to her, she was outstanding. Look, I've just won a silver medal in a world championship, so I shouldn't get too down on myself, but it was a bit ugly out there towards the end."
2009 Perth ITU Long Distance Triathlon World Championships - Perth, AUS
3-kilometre swim, 80-kilometre bike, 20-kilometre run
Gold - Tim O'Donnell (USA) 3:48:15.
Silver - Sylvain Sudrie (FRA) 3:49:22.
Bronze - Martin Jensen (DEN) 3:49:34.
4. Jan Rehula (CZE)
5. Paul Ambrose (GBR)
6. Francois Chabaud (FRA)
7. Leon Griffin (AUS)
8. Julien Loy (FRA)
9. Kieran Doe (NZR)
10. Clayton Fettell (AUS)
Gold - Jodie Swallow (GBR) 4:07:38.
Silver - Rebekah Keat (AUS) 4:18:49.
Bronze - Delphine Pelletier (FRA) 4:19:27.
4. Sibylle Matter (SUI)
5. Lucie Zelenkova (CZE)
6. Amelia Pearson (AUS)
7. Lisa Marangon (AUS)
8. Merja Kivaranta (FIN)
9. Pip Taylor (AUS)
10. Rebecca Witinok-Huber (USA)