KEY BISCAYNE, Florida — Lauren Davis defeated Zhang Shuai of China 6-2, 6-3 at the Sony Open Wednesday as former US Open champion Juan Martin del Potro withdrew with a left wrist injury. The 20-year-old Davis started 2014 ranked No. 72 and moved up to No. 55. From 1-1 in the first set, Davis jumped ahead to a 4-1 lead. In the second set, Zhang started with a 3-1 lead, but Davis won the next five games to take the match. Fellow American Christina McHale defeated Zheng Jie of China 6-4, 6-2. Wildcard recipient Victoria Duval didn't fare as well as her fellow Americans, losing to Dutch qualifier Kiki Bertens 7-6 (5), 6-1. Del Potro has been troubled by his left wrist since winning the Sydney title at the beginning of the year. At the recent Indian Wells tournament he played one doubles match, but then withdrew from the singles. The 37th-ranked Andrea Petkovic of Germany, a top 10 player in 2011, posted a 6-3, 6-4 win over Maria-Teresa Torro-Flor of Spain. In first round men's action, 80th-ranked Adrian Mannarino of France ousted 71st-ranked Nikolay Davydenko of Russia 6-4, 7-5. Czech Radek Stepanek defeated Daniel Brands of Germany 6-3, 6-0. Ivo Karlovic of Croatia claimed up a tough 7-6 (3), 7-6 (5) win over French qualifier Paul-Henri Matthieu. The loss of eighth seed del Potro, still suffering with the left wrist injury that has compromised his season, could deliver a box-office blow to the event with plenty of South American supporters in the Miami area. “I still feel pain in my left wrist and I don't feel competitive to go on court,” Del Potro said. “It's a pity because this is a special tournament for me since there are many Latin fans and Argentines in particular. In the next few days I will visit my doctor again to determine the following steps.” German lucky loser Benjamin Becker replaced del Potro in the draw, which has all seeds given byes into the second round. — Agencies
