Eugenie Bouchard has survived a tough challenge from Sorana Cirstea to record a 6-2 6-7 6-4 victory in the second round of the US Open.

It was a strong start to the match for the Canadian, who broke Cirstea's serve in just the second game to claim an early advantage in New York.

Bouchard was forced to overcome a test on her own serve later in the set when she saved a break point shortly before taking the opener when Cirstea's service frailties returned.

History repeated itself as Cirstea was broken early in the second set, but the Romanian quickly responded to earn parity with the seventh seed.

There was more drama to come, though, as the rivals exchanged two further breaks of serve to set up a tie-break, which Cirstea won 7-4.

A break of serve each early in the decider left the contest delicately poised, and it was the underdog who blinked first as Cirstea gifted the lead to Bouchard in the seventh game.

The 24-year-old then managed to save a match point, but Bouchard refused to be denied the victory, and she served out to continue her bid for a first Grand Slam title.