WELLINGTON -- New Zealand's Olympic gold medalist Rob Waddell won the second race on Monday in the battle for who will represent New Zealand in the single sculls at the Beijing Games.

Triple world champion Mahe Drysdale won the first 2000 m race by a boat length at Lake Karapiro, New Zealand, on Sunday.

Waddell, a gold medalist at the Sydney Games in 2000 and double world champion, won by half a boat length on Monday.

The final race will be held on Tuesday. Only one person can represent New Zealand in the single sculls event.

The battle between Drysdale, 26, and Waddell, 33, has gone on all summer, with Waddell winning three of their previous four clashes.

Waddell announced a comeback to rowing last year after being a member of the Team New Zealand America's Cup defence team in 2003 and the challenger team in 2007.

The selection will be decided by the New Zealand Olympic Committee and an announcement is due on Friday.

There is hope that the loser of the duel could still go to the Beijing Games in August as part of another rowing combination.