Michael Phelps' roller-coaster ride in Rome continues. The Beijing Olympics hero retained his 200 metre butterfly world title and smashed his own world record to reassert his authority after a tough 24 hours at the FINA swimming championships.

The American lost his 200 freestyle world record to Germany's Paul Biedermann, but he burst back to the top with an awesome display of power one day later. Phelps got off to a good start in the 200 butterfly and slid into a comfortable tempo from then on.

He established a comfortable lead over his rivals in less than 40 seconds. Phelps increased his advantage and darted to the finish line in a time of 1 minute 51.51 seconds, setting a new world record.

Meanwhile, Local heroine Federica Pellegrini stormed to victory in the women's 200 freestyle final, further shattering the world record she had already broken in Tuesday's semi-finals. The Italian clocked 1 minute 52.98 seconds to chalk up a freestyle double. Pellegrini triumphed in the 400 on Sunday.

South African Cameron van der Burgh made sure he did not miss out on the party by battering his own world record to take gold in the men's 50 breaststroke. He also set the previous best mark in Tuesday's semi-finals.

(CCTV July 30, 2009)