Mahan extended his streak to 166 holes without trailing and defeated Ian Poulter on the strength of his chipping. Mahan won, 4 and 3, giving him a chance to join Tiger Woods as the only back-to-back winners in 15 years of this tournament.
Mahan twice hit tough chips to win the hole and build a 2-up lead at the turn, and he chipped in for birdie on the 12th hole to seize control.
Kuchar advanced to the final match for the first time. He won three holes late on the front nine and was never challenged after that in a 4-and-3 victory over Jason Day of Australia.