Tennis-Halep beats Azarenka to reach US Open semi-finals

By Larry Fine NEW YORK, Sept 9 (Reuters) - Second seed Simona Halep fought off a determined challenge from former world number one Victoria Azarenka to advance to the semi-finals of the U.S. Open with a 6-3 4-6 6-4 victory on Wednesday. The 23-year-old Halep, of Romania, chasing her first grand slam singles title, came out strong against the Belarussian after an 85-minute, third-set rain delay to earn a last-four clash against Italy's Flavia Pennetta. Pennetta, 33, ousted twice Wimbledon winner Petra Kvitova, the fifth-seeded Czech, in three sets, to advance. Top seed Serena Williams, bidding to complete the fourth women's calendar-year Grand Slam sweep, faces Roberta Vinci of Italy in Thursday's other scheduled semi-final. (Editing by Andrew Both)