Lee Chong Wei started the 2009 season with his fifth Malaysia Open title. He failed to secure his first Korea Open and All England Open title despite marching into the final. However, he secured his second title of the year in the Swiss Open which was held in Basel, defeating Lin Dan in straight sets and marking his first win in the finals against the Chinese opponent outside home turf. Next, Lee was surprisingly defeated by Chen Long of China in the India Open. He cited the loss was due to food poisoning and insisted the authorities improve the conditions before the World Championships. In May, Lee helped Malaysia reach the semi-finals of the Sudirman Cup, the first in national history, despite his unbeaten record in the tournament being blown out by Lin Dan. He won another two titles in June, the Indonesia Open and the Malaysia Open Grand Prix Gold, despite failing to defend his Singapore Open title when he was taken by Nguyen Tien Minh in the second round.

Lee kicked off the second half of the season with defeat by Sony Dwi Kuncoro in the world meets, but went on to win the Macau Open in August. He reached the semi-final in the China Masters, but once again failed to beat his all time rival Lin Dan. Then, Lee participated in the Japan Open. He only managed to reach the second round of the Open, before winning the Hong Kong Open in November. His inconsistency saw him tumble down in the first round of the China Open. In December, Lee defended his Super Series Masters Finals title, which saw the competition played without the top badminton players in the world.

Doping[edit]
2016[edit]
2011[edit]
2009[edit]