American swimmer Michael Phelps aims to win two more Olympic gold medals on Wednesday as he steamed ahead in his eight-gold quest in Beijing.

Phelps has claimed three Olympic titles in the first three days of races in 400-meter individual medley, 4X100m freestyle relay and 200m free.

He remains virtually unchallenged in the 200m butterfly final, in which he came out top in Tuesday's heats at one minute 53.70 seconds.

Phelps is the defending Olympic champion in the event and holds its world record at 1:52.09, which he set in the 2007 Melbourne World Championships. He has rewritten the record six times since 2001.

China's Wu Peng, silver medallist in Melbourne, entered into the final as the fifth seed. Wu will contend with Hungarian Laszlo Cseh for the minor medals.

Phelps' fifth gold chance rests in the men's 4X200m freestyle, in which he holds the world record with teammates at 7:03.24. The Americans went out strongly in the heats to cap the final list of swimmers, clocking 7:04.66, more than three seconds faster than Italians and Russians.

Italian swimmer Federica Pellegrini, who swam a new world record at 1:55.45 on Monday, is expected to dominate the field in the women's 200m free.

The 400m free gold medal has eluded the 20-year-old swimmer, who also set a new world record in the heats but lost the final to the lesser-known Briton Rebecca Adlington.

American Katie Hoff, who has won a silver and a bronze in Beijing, is rooting for another medal. Chinese sprinter Pang Jiaying pushed herself to a personal best of 1:57.34 in Tuesday's semifinal.

The women's 200m individual medley final will see a three-way battle between Hoff, Zimbabwean Kirsty Coventry and Australian Stephanie Rice.

Rice, an Olympic debutant, was crowned in the 400m individual medley with a new world record. She holds the 200m medley world record at 2:08.92.

(Xinhua News Agency August 12,2008)