US superstar Simone Biles claimed her third gold in Rio on Sunday in the women's vault as Max Whitlock gave Britain their first Olympic gymnastics crown in the men's floor.

The 19-year-old Texan, bidding for an unprecedented five women's gold in Rio, added to her all-around and team titles with the beam and floor finals to come next week.

She scored a combined 15.966 after two powerful vaults -- 15.900 and 16.033 -- to take gold ahead of world champion Maria Paseka of Russia (15.253).

Swiss Giulia Steingruber (15.216) took bronze in the Rio Olympics Arena.

Earlier Whitlock claimed a first gold for his country as Japanese star Kohei Uchimura had to settle for fifth best on the floor.

The 23-year-old Whitlock scored 15.633 points to achieve his fourth Olympic medal and second in Rio after all-around bronze.

Whitlock could claim more gold on Sunday as he competes on the pommel horse on which he is the reigning world champion.

Brazilian duo Diego Hypolito (15.533) and Arthur Mariano (15.433) won silver and bronze respectively to the delight of the home crowd in the Rio Olympic Arena.

"For me this is a gold," said an emotional Hypolito, a world champion on floor in 2005 and 2007 but who fell during the event in Beijing 2008 and London 2012.

"Winning a medal today was the most important thing in my life," the 30-year-old added.

Uchimura had been bidding for a third gold in Rio following team and all-around but complaining of a sore back he was clearly off form as he hopped off the mat during his routine. He scored 15.241 to finish fifth.

Two-time world floor champion Kenzo Shirai of Japan dropped to fourth (15.366) after an error-strewn performance.

"This felt very different to when I was doing the team event," said Shirai, who helped Japan to the team title.

"When I was doing the team, I felt that we were pushing each other's backs, propelling each other along. This one I felt like I was very much alone."

The only apparatus final Biles failed to qualify for was the uneven bars which takes place later Sunday.