James DeGale won the IBF super-middleweight title with a thrilling victory over Andre Dirrell in Boston.

The 29-year-old dropped Dirrell twice in the second round and, although the American worked his way back into the fight, he could not do enough to deny DeGale becoming the first Olympic gold medallist from Great Britain to win a world title.

DeGale took the opening round, but there were signs at the start of the second that Dirrell had found his range as he inflicted a cut just above his opponent's right eye.

However, the injury spurred DeGale into life and he sent Dirrell crashing to the canvas with a huge left hand, which the Michigan native survived, but he was soon on the floor for a second time before the bell.

Dirrell was on the end of more significant shots in the third, but he had regained his composure by the fifth and it appeared as though he won the following five rounds as DeGale retreated, perhaps to conserve energy for down the stretch.

Dirrell got the better of the 10th, but the final two sessions were left open to debate as DeGale produced more of the work that had proven so effective in the opening part of the fight.

The contest could have gone either away, but all three judges scored the fight in favour of DeGale by scores of 114-112, 114-112 and 117-109 respectively.