Heather Watson could not join fellow Briton Laura Robson in the US Open second round as she was beaten in three sets by Simona Halep at Flushing Meadows.

Robson won convincingly in New York on Monday and Watson looked on course to follow her compatriot's example when she claimed an error-strewn first set.

Each player lost two games on their own serve before Watson gained what was the decisive fifth break to win the opener 6-4 and take an advantage in the contest.

Britain's number two levelled the second set at 3-3 after immediately recovering from losing a break, but her Romanian opponent broke again to earn parity and force a decider.

Watson lost her three opening service games in the third set as Halep, a winner at the New Haven Open last week, moved into a 5-1 lead, and the world-number 19 went on to claim the match 4-6 6-4 6-2 in just under two hours.