The Russian, who is playing at a first Grand Slam since she completed a 15 month doping ban earlier this year, recovered from losing the first set to defeat Hungarian opponent Timea Babos at Flushing Meadows today.

Sharapova triumphed 6-7(4), 6-4, 6-1 to follow her opening round win over Romanian second seed Simona Halep.

"I felt like it was a scrappy match but sometimes those days are the best, because you get through and give yourself another chance," said the 30-year-old, who is only competing by virtue of a wildcard after her world ranking slumped to 146th.

Her presence is still not universally popular among her peers, however, with 20th seed CoCo Vandeweghe among those to question the awarding of the wildcard.

The American admitted that "she can't say I agree" with the decision before "selfishly" expressing a wish that it had gone to another home player.

Vandeweghe beat fellow countrywomen Alison Riske 2-6, 6-3, 6-4 elsewhere today while eighth seed Svetlana Kuznetsova of Russia survived three match points before defeating Czech Republic's Marketa Vondrousova 4-6, 6-4, 7-6(2).

France's 14th seed Kristina Mladenovic was the most high profile casualty after losing 6-3, 6-2 to Romanian Monica Niculescu.

There were few shocks in the men's singles draw today.

Top ranked American and 10th seed John Isner powered down 30 aces in a 6-3, 6-4, 7-5 win over Hyeon Chung of South Korea.

Sixth seed Dominic Thiem was the highest ranked player to advance after completing a 6-4, 6-1, 6-1 rout of Australian Alex di Minaur in a delayed first round match halted due to rain yesterday.