Lin Dan took the title

Olympic badminton champion Lin Dan had an ideal preparation for his title defence when he won his fourth world title on Sunday in the Wembley arena to be used for the 2012 Games.

The second-seeded Chinese player saved two match points against top-seeded Malaysian Lee Chong Wei and went on to a 20-22, 21-17, 23-21 victory. It was probably the best encounter of the 24 between the two great rivals.

Lin's triumph was the highlight of a day in which China became the first country to successfully defend all five world titles.

China's Dan Lin celebrates after beating Malaysia's Chong Wei Lee in the men's singles final at the badminton world championships on Sunday.

He rarely dominated and there were moments, particularly at 16-13 in the final game, when it seemed Lee's court coverage, patience and ability to turn defence into attack would secure victory.

But when it mattered, it was Lin who delivered. He saved one match point at 19-20 in the final game with an airborne smash, and the other at 20-21 with a lift to the back which drew an overhead drop into the net from Lee.

He then played two cagey points which resulted in two more Lee errors that ended the match, leaving the impression that after 81 minutes of constant pressure the difference between the two men was mental.

"The third set was very emotional. I had to fight so hard," said Lin, who played down his Olympic hopes.

"If I can represent China in London, it would be a great honour for me," he said. "I don't think about next year too much, I will see what happens. There is a very high demand with so many tournaments. I want to prepare and rest so I can do well in them."

Lee did not talk to the media afterward, but his coach Tay Seu Mo said: "Chong Wei missed two match points because at the end of the game he still dared to gamble on his strokes. But mentally Lin Dan was a little stronger."

China followed up by taking the women's singles title.

Wang Yihuan, the second-seeded former All-England champion, beat seventh-seeded Cheng Shao Chieh from Taiwan 21-15, 21-10, after recovering from a slow start in which she went 9-12 down.

Wang Xiaoli and Yu Yang won the women's doubles event, while the men's doubles title went to Cai Yun and Fu Haifeng, who won it for a fourth time.

The clean sweep of five titles was completed in the mixed doubles when Zhang Nan and Zhao Yunlei accelerated from 15-15 in the first game to win 21-15, 21-7 against Britain's Chris Adcock and Imogen Bankier.