Isner and Harrison advance to semis

Defending champion John Isner hammered 12 aces to beat Izak van der Merwe 6-4, 7-6 (7/2) to reach the semi-finals of the ATP Tour\'s Hall of Fame Tennis Championships on Friday. Top seeded Isner will square off against fellow American Ryan Harrison who was leading 6-4, 3-0 in his quarter-final when Benjamin Becker, of Germany, retired with an injury. Isner won 85 percent of his first-serve points against the South African qualifier on the grass courts. Isner beat Belgian Olivier Rochus in last year\'s final in Newport. Australian veteran Lleyton Hewitt will face American Rajeev Ram in Saturday\'s other semi-final. Hewitt is a two-time major championship winner and Ram won this event three years ago.