John Isner through to Houston semi-finals in straight sets

Top seed John Isner advanced to the semi-finals of the Fayez Sarofim & Co. U.S. Men's Clay Court Championship in Houston with a straight-sets win over Hyeon Chung.

Isner sent down 14 aces and saved all seven break points he faced to set up a last-four clash with Jack Sock after the 7-6 (7/5) 6-4 win.