American Christina McHale and Chanelle Scheepers of South Africa were among Tuesday\'s first-round winners at the Mercury Insurance Open. McHale, the fifth seed, defeated Jarmila Gajdosova 7-6 (7-5), 7-5. Scheepers, the eighth seed, topped Coco Vandeweghe 6-2, 7-6 (7-4). American Vania King eliminated Kai-Chen Chang 6-1, 6-4 and Yung-Jan Chan of Taiwan advanced when seventh-seeded Yanina Wickmayer retired trailing 7-6 (8-6) after one set. New Zealand\'s Marina Erakovic, Hungarian Melinda Czink, Britain\'s Heather Watson and American Melanie Oudin also posted wins Tuesday.