LONDON - China's Zou Kai presented a flawless routine on floor exercise on Sunday, successfully defend the title on which he won four years ago.

Zou, as the top finisher in the qualification, improved his leading qualifying score to reach a lofty 15.933 points, overtaking the reigning world champion Kohei Uchimura of Japan, who pulled out 15.800 points as the starter.

Russia's Denis Ablyazin shared a 15.800 with Uchimura, but a lower execution point pushed him to bronze medal.

Uchimura took 9.1 points in execution against Ablyazin's 8.7, but the leading 7.1 of difficulty score, 0.2 more than Zou, propelled the Russian to the third place.

"I have expected Uchimura to have a high score and I'm mentally prepared for this, so the result came out from him would not affect me much," said Zou.

"I'm at competition like this, you have no tactics at all. What you can do is to get yourself prepared mentally. The outcome proved that I'v prepared myself well."

Zou became the second athlete to win twice the men's floor exercise at Olympic Games after Nikolai Andrianov of Soviet Union in 1972 and 1976.

Zou set the all-time record of five Olympic gold medals among Chinese gymnasts.

"Now I have five Olympic golds, the most among all Chinese. It means a lot for me and I can show this to my child some day," said Zou, who becomes the most prolific Chinese on Olympic stage and possibly to add another gold two days later on horizontal bar.

"The gold medal is an encouragement and confidence builder for me and I hope I will do good on horizontal the day after tomorrow," added Zou.

Uchimura was pleased with the second place though he aspired for the gold. "I'm eager to win the gold medal as what I did last year, but I have to admit the Chinese gymnast did better than me and I'm pleased with my performance today and with the silver," said Uchimura.

To Ablyazin, a podium finish is something satisfactory. "I was nervous when I saw to scores from the top two competitors," said the Russian, who was placed only 10th at the 2011 worlds.

"But I told me I need to try my best. I won't let the team competition result (where Russians finished sixth) affect me. I'm happy to win a medal on floor," said the 20-year-old Russian.