Isner will face the fourth-seeded defending champion Jack Sock of the United States, a 6-4, 6-4 winner over seventh-seeded
In afternoon matches at River Oaks, Argentina's
In doubles, American twins Bob and Mike Bryan advanced to the final, beating Querrey and Steve Johnson 7-6 (5), 6-3. The Bryans have won the event five times and have 109 team titles.
Kerber, the top seed, will face No. 7
The other semifinal Saturday features fifth-seeded