Olympic champions Qin Kai and Wang Feng of China defended their world championship title in 3-meter synchronized diving on Saturday, beating Troy Dumais and Kristian Ipsen of the United States in the six-dive final.

Qin and Wang compiled 467.94 points to win the gold medal on the second day of the swimming world championships at the Foro Italico. Dumais and Ipsen took silver with 445.59 points and Alexandre Despatie and Reuben Ross of Canada were third with 428.64.

The 29-year-old Dumais and 16-year-old Ipsen blend youth and experience. The pair only began training together in March, yet they remained in the top three positions after each round.

Dumais is appearing in his sixth worlds, having previously won three medals _ silver on 3-meter and bronze on 3-meter synchro in 2005 and silver on 1-meter in 1998.

This is Ipsen's first worlds, having won a junior world championship on 1-meter in 2006.

"I was pretty confident during prelims. In finals I was more nervous because I've never had a meet this big, but Troy calmed me down," Ipsen said.

Canada's Despatie earned his seventh medal at worlds.

Earlier, Paola Espinosa of Mexico upset Olympic champion Chen Ruolin for the gold medal in women's 10-meter platform.

Espinosa scored 428.25 points through five dives from in highest event. Chen took the silver medal with 417.60 points and Kang Li of China was third with 410.35.

Espinosa scored a 10 on her second dive, a back 3 1/2 somersault tuck, and another perfect score in round 3 with a reverse 3 1/2 somersault tuck.

It was the first gold medal for Mexico at the swimming worlds, which have been held since 1973.

During the news conference afterward, Espinosa received a congratulatory call from Mexican President Felipe Calderon.

"I have worked hard all my life, my ambition is confirmed with a gold medal," said Espinosa, who finished fourth in 10-meter platform at last summer's Beijing Games.

Elsewhere, rough seas forced organizers to rearrange the schedule for open water swimming events.

The men's and women's 5-kilometer races scheduled for Sunday have been pushed back to Tuesday, both 10K races will be held Thursday and both 25K events will take place next Saturday.

In synchronized swimming, overwhelming favorite Russia led the team technical preliminaries, with Spain second and China third.