Defending champion Jack Sock beat top-seeded John Isner 7-6 (7-4), 6-3 Saturday to reach the final of the ATP clay court tournament in Houston. America's Sock, seeded fourth, will be trying to become the first player since Andy Roddick in 2001-02 to repeat as the Houston champion when he takes on Argentina's Juan Monaco. Monaco, the 2012 Houston winner, defeated third-seeded Spaniard Feliciano Lopez 6-4, 6-2. "It's always tough to play a good friend like John," said Sock, whose Houston title remains his only ATP championship. "But I'm happy to get through. I love playing in this city, on this court." Isner, struggling with knee trouble, had treatment from a trainer, and Sock, 23, acknowledged he tried to capitalize on that. Isner fired 14 aces, but Sock notched the only break of the match in the second set. Monaco, 32, is seeking his first ATP title since he lifted the trophy in Duesseldorf in 2013. A former top 10 player, Monaco is playing in just his fifth tour-level tournament of the year. Stephens up against Vesnina In Charleston, Sloane Stephens reached her third WTA final of the year when top-seeded Angelique Kerber of Germany retired in the second set of their semifinal at the Volvo Car Open Saturday due to a viral illness. Seventh seed Stephens had dominated the match played in blustery conditions on the green clay in Charleston, leading 6-1, 3-0 when Australian Open champion Kerber waved an end to the match. The 23-year-old American will face Russian qualifier Elena Vesnina, 29, who ousted fifth-seeded Sara Errani of Italy 6-4, 4-6, 6-2 in a battle that stretched for two hours and 20 minutes. Kerber was attended to by trainers after losing her serve to the American to fall behind 2-0 in the second set, but gave it another try before deciding to retire. Stephens, who has won titles this year at Auckland and Acapulco, was in total command of her game, hitting 14 winners while committing only four unforced errors in the match and did not face a single break point. Vesnina, who won the mixed doubles title at the Australian Open with Brazilian Bruno Soares, made the critical break in the sixth game of the third set for a 4-2 lead and broke again to secure her place in Sunday's final. — Agencies
