Dimitrov knocks off Steve Johnson to reach Cincinnati semis

MASON, Ohio (AP) Grigor Dimitrov reached the semifinals of a Masters event for the third time, beating top American Steve Johnson at the Western & Southern Open on Friday.

Dimitrov's 7-6 (8), 6-2 victory made him the first to reach the semifinals in a tournament missing the top players. Andy Murray is the only defending champion left in the field. He plays on Friday night.

Novak Djokovic and Roger Federer are hurt, and Rafael Nadal is still getting back into playing shape after a wrist injury cost him two months. That cleared the way for the unseeded Dimitrov and others to try for a Masters title.

Despite the loss, Johnson will become the top American in the ATP rankings next week. John Isner has held the top spot since July 29, 2013.