With Grant Hackett's win in men's 400m freestyle and the female team's victory in 4x100m free relay, Australia upstaged the United States as the duel between the two swimming powerhouses triggered at World Aquatic Championships on Sunday in Montreal.

Australian captain Hackett entered the 400m free final with 3 minutes 44.63 seconds, the fastest time in prelimnary. Later, the 25-year-old giant grabbed his first world champion title over this distance by clocking at 3:42.91.

"I'm certainly happy," Hackett said, "It was an important first day."

In fact, the famed distance king is also an extremely excellent mid-distance freestyle expert but in the shadow of his teammate Thorpe for a long time.

When Thorpe fabulously achieved his third consecutive win in 400m free at Barcelona World Championships two years ago, Hackett received the silver medal over this distance, also at successive three World Championships. Besides, Hackett finished second in the event at Athens Olympics and the only man swam faster than him in the final was Thorpe again.

As "Thorpedo" was saving energy for 2008 Beijing Olympics, Hackett knew that his winning chance in 400m free finally came and didn't let it slip off his grip.

Yuri Prilukov of Russia and Tunisian swimmer Oussama Mellouli finished second and third respectively.

However, American wunderkind Michael Phelps produced the biggest shock of the day as he faild to qualified for the final, not to mention rivaling head-to-head with Hackett.

The 20-year-old American stunningly grabbed an 18th position among 57 swimmers in the preliminary, and even himself didn't know what happened.

"It didn't go the way I wanted it to start off. I'm pretty disappointed. I felt good in the warm up, and then in the race I wasn't there."

After a frustrating morning, the eight-time medallist at Athens Olympics did a good job later on Sunday night as he took off for the U.S. 4x100m free relay in the final and grabbed the gold with his teammates in a new championships record of 3:13.77. The former record created by the Russian team in Barcelona is 3:14.06.

"I'm happier tonight than I was this morning," Phelps said. "I'm pleased with my race. It's definitely a step up from this morning, and we have more races ahead."

The other two swimming golds on Sunday were both grabbed by the Olympic champions in the same events.

18-year-old Laure Manaudou of France, who came out hot favoured for the title in women's 400m freestyle, clocking at 4:06.44 in the final in Montreal and snatched her first world champion title.

Ai Shibata of Japan, the Olympic medallist in the 800m freestyle also showed a rousing style as she took the silver 0.30 second behind Manaudou. Caitlin McClatchey of Britain finished third in 4:07.25.

The powerful Australian women team was still unbeatable in the 4x100m free relay. After taking victory in Athens by smashing the world record, the Aussies registered a new championships record of 3:37.32 and grabbed the gold at the same time.

The German and the American teams received silver and bronze medals respectively.

Some more new records added highlights for the first- day swimming competitions. Jessicah Schipper of Australia broke twice the championships record of women'100m butterfly, prior to the final of this event on Monday.

Japan star Kosuke Kitajima smashed the championships record of men's 100m breaststroke in the heat but entered the final with the second fastest time in the semi-final, behind arch-rival Brendan Hansen of the United States.

Roland Schoeman, the "Flying man" of South Africa shattered men's 50m freestyle world record in the semi-final.

The rivalry between Kitajima and Hansen will cetainly become the center in the swimming pool on Monday. Besides, Phelps has to try his best in the 200m freestyle preliminary and semi-final, so as not to miss his second individual final.

Source: Xinhua