Golf-Merritt leads by three, Spieth in the hunt at Hilton Head

April 18 (Reuters) - Unheralded American Troy Merritt moved one step closer to his maiden PGA Tour title by claiming a three-stroke lead after Saturday's third round of the RBC Heritage in South Carolina. Merritt, ranked 249th in the world and playing in his 86th tour event, followed his course record-tying 61 in the second round with a 69 for a 54-hole total of 14-under-par 199 on the Harbour Town Golf Links on Hilton Head Island. Tied for second place on 11 under par after a warm, sunny day were defending champion Matt Kuchar, who shot a 68, and fellow Americans Brendon Todd (63) and Kevin Kisner (67). One more shot back were 2010 winner Jim Furyk (68), Brice Garnett (65) and Branden Grace of South Africa (66). Masters champion Jordan Spieth stayed in the hunt, shooting a 68 for a 204 total, five shots off the pace along with Bo Van Pelt (67). Seven players were tied at 205, including England's Luke Donald, Brendon de Jonge of Zimbabwe, Northern Irishman Graeme McDowell and South African Louis Oosthuizen. (Reporting by Larry Fine in New York; Editing by Gene Cherry)