ERFURT, Germany (AP) — Robert Stieglitz of Germany has kept his WBO super middleweight title with a unanimous decision over Nader Hamdan of Australia.

Stieglitz dominated the 12 rounds Saturday night, but was forced to go the distance by a 38-year-old challenger who was called up as a late replacement for Britain's George Groves. Groves pulled out last month because of an undisclosed injury.

The judges scored the fight 120-108, 117-111 and 117-111.

The 30-year-old Stieglitz improved to 42-2 (23 KOs) while Hamdan dropped to 43-10-1 (18 KOs).

Stieglitz will next face mandatory challenger Arthur Abraham of Germany on Aug. 25.