Indonesia's Tontowi Ahmad and Liliyana Natsir defeated Chan Peng Soon and Goh Liu Ying of Malaysia to win Olympic gold in the badminton mixed doubles on Wednesday.

The Indonesian pair took the first game 21-14 before completing the victory with a 21-12 triumph in the second, delighting a noisy contingent of Indonesian fans who chanted their country's name throughout.

Ahmad and Natsir had stunned top seeds and defending champions Zhang Nan and Zhao Yunlei of China in the semis and brought their sensational form into the final, dominating from the outset.

Their victory never looked in doubt as they won both games with relative ease due to an array of excellent shot-making and some unenforced errors from the Malaysian couple.

Ahmad, 29, sank to his knees and banged the floor with his hands in celebration before running over to the Indonesian spectators to receive their acclaim.

It was a first Olympic gold medal for both Ahmad and 30-year-old Natsir, who adds to her mixed doubles silver won at the 2008 Beijing Games.

The defeat was further heartache for badminton-mad Malaysia who are yet to win an Olympic gold medal in any sport.