HOUSTON (Reuters) - American wild card Ryan Sweeting completed his unlikely tournament run by capturing the U.S. Clay Court Championship with a 6-4 7-6 victory over Japan's Kei Nishikori on Sunday.

Sweeting, who managed to fend off a set point in the second set, became the first player to win the tournament as a wild card entry since fellow American Mardy Fish in 2006.

Sweeting, who overcame six double faults for the match, did not face a break point in winning the first set but needed to climb out of a 5-4 deficit and a set point to force a tiebreaker in the second set.

The 23-year-old American, born in the Bahamas but a resident of Fort Lauderdale, Florida, will move up to 71st in the world, a career-best ranking.

(Reporting by Jahmal Corner in Los Angeles; Editing by Frank Pingue)