Graeme Brown won his second gold medal of the Olympics when he and Stuart O'Grady defended Australia's title in the 50km madison race.

The 4000 team pursuit champion linked with the road race specialist to repeat the gold won by Brett Aitken and Scott McGrory in Sydney four years ago and continue Australia's dominance at the Olympic Velodrome.

Australia won with 22 points and a lap up on the field in the two-man team event, with Switzerland second on 15 and Great Britain taking bronze with 12.

O'Grady was controversially drafted in from the road race team to replace Mark Renshaw who attacked selectors for dumping him from the madison.

But the South Australian vindicated their decision to win his first Olympic gold after team pursuit silver in 1996 and a pair of bronze in 1996 from the points race and team pursuit.

With 138 laps to go in the 200 lap event, O'Grady and Germany's Guido Fulst led out a two-pronged attack and both teams gained a lap on the field.

O'Grady won the next sprint to take Australia into the lead on eight points with Germany second on five, but both with a lap on the rest of the field.

O'Grady and Brown teamed brilliantly and took points from every sprint and when Brown earned points from the second last sprint, he took Australia to an unassailable lead with 19 points.

Britain had gained a lap to join Switzerland in second place on 10 points, but the Australians could not be caught.

Spain and New Zealand made a desperate bid to gain an extra lap on the Australians, but Brown and O'Grady stayed with them to wrap up the gold.

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