Sun Yang will be favorite to win his second gold medal of the London Olympic Games when he swims the final of the men's 1,500 meters freestyle on Saturday.

The world record holder, who won the 400 meters freestyle earlier in the week and who also has bronze medals from the 200 meters and 4x200 meter relay, swam almost three seconds faster than anyone else in Thursday's 1,500 meters semi-final.

Yang Sun of China wins his 1500m heat.

Sun's time of 14:43.25 was comfortably clear of Tunisia's Oussama Mellouli, who swam 14:46.23 and Canadian, Ryan Cochrane, who finished in a time of 14:49.31. Great Britain's Martin Fogg and South Korean Park Taehwan also made it to the final, but given that he was conserving his energy, it is hard to see anyone stopping Sun.

"We are all in the race for gold, but my aim is to produce a race I can be proud of,"said Cochrane.

The morning began with the heats of the women's 50 meters freestyle and 100 meters gold medalist, Romoni Kromowidjojo was fastest off the blocks and across the pool in a time of 24.51, while the slowest qualifier, Anna Santamans needed just 25.23 in a 'blink and you miss it' series of races.

"I went to bed at midnight and I got up at 7am. All I could think about is 'gold, gold, gold.' It's madness,"said Kromowidjojo.

There were few surprises in the 4x100 meters women's medley as Australia, Japan, Denmark, the United States, the Netherlands, China, Great Britain and Russia qualified for the final. The qualifying times are not particularly relevant as most of the favorites will make changes to their line-ups for the final.

The same is true for the men's 4X100 meters medley relay, which will be Michael Phelps'last competitive swim after the US quartet assured their place in the final, by finishing 0.81 seconds ahead of the British quarter, who clocked the second fastest time. The Australians will need to improve if they are to win a medal after making only the fourth fastest time in qualifying.

It has been a relatively disappointing Olympics for the Australians, who arrived in London with high hopes, but who so far have claimed only one gold and have been beaten in most head-to-head confrontations by the Americans over the past week.