Beijing - Americans Rebecca Soni and Ryan Lochte won the first two gold medals on offer Friday at the Beijing Olympics, as they swam world records in the women's 200-metre breaststroke and men's 200m backstroke respectively.

Soni, who lost to Australian Leisel Jones in the 100m breaststroke, prevailed this time around, winning in a time of two minutes 20.22 seconds, beating Jones by 1.83 seconds.

Both swimmers were under the previous best mark set by Jones in Melbourne two years ago.

Third place went to Norwegian Sara Nordenstam, who swam a European record in 2:23.02.

In the men's 200m backstroke Lochte won his first individual Olympic gold medal as he beat 100m backstroke champion Aaron Peirsol, with whom he shared the world record going into the swim.

Lochte had a time of 1:53.94, beating Peirsol by 0.39 seconds. The previous record stood at 1:54.32.

Lochte swim was the 20th world record in the Beijing Water Cube at these Olympics.

Russian Arkady Vyatchanin established a European record for the bronze medal in 1:54.93.

In the men's 50m freestyle semi-finals Brazilian Cesar Cielo showed that he is the man to beat as he qualified for the final with the fastest time of 21.34, breaking the Olympic record he held for a few minutes on Thursday by 0.10 seconds.

There was an upset in the women's 200m backstroke semi-final as France's Laure Manaudou, who was considered as one of the favourites, failed to qualify for the final as she managed only the 14th fastest time in 2:12.04, well off the pace set by Zimbabwean Kirsty Coventry, who won her heat in 2:07.76. (dpa)