The wild card might have been controversial, but Maria Sharapova showed she still has it by beating the No.2 seed Simona Halep in a pulsating first round match at the US Open 2017 on Monday.

Seemingly down and out after being denied an entry to the French Open and having missed Wimbledon through injury, Sharapova grabbed this opportunity presented by the USTA with both hands to move onto the second round.

The former champion brought out all that big-match experience to play, seeing off Halep 6-4, 4-6, 6-3 in two hours and 42 minutes.

After clinching the first set and then going up a break in the second, it looked like Sharapova would cruise past the Romanian, the finalist at this year's French Open, only for Halep to fight back brilliantly.

And you felt, courtesy that fightback from Halep, Sharapova, still making tentative steps back into the main fold following her 15-month doping ban, would lose her legs and mettle in the final set.

However, it proved to be the other way around.

Sharapova, cheered on by the New York crowd, was the one who grabbed an early break, and despite plenty of pressure from Halep, including a break back point while the Russian was serving for the match, she held her nerve to clinch the match and keep her hopes of making a stunning Grand Slam comeback alive.

Maria Sharapova, US Open 2017, Simona Halep
Maria Sharapova was brilliant on her Grand Slam comeback, August 28, 2017Clive Brunskill/Getty Images

You could see just what the win meant for Sharapova, who fired in 60 winners to Halep's 15, with the veteran dropping down to her knees as she soaked in the applause and that feeling of winning a big match in the big stage again.

Earlier, another seeded player was knocked out in the first round as Johanna Konta made an early exit from New York. The No. 7 was upset by Aleksandra Krunic, ranked 78 in the world, 4-6, 6-3, 6-4 in two hours and 16 minutes.

Konta, who impressed at Wimbledon by reaching the semifinals, just could not get her serving going – her first-serve percentage was a paltry 45 per cent – and that proved to be the difference as Krunic put up some impressive winners.

"I don't think I necessarily played my best tennis, but my opponent also had something to say about that," Konta said.

"She played very freely, I felt, and she moved incredibly well. She made it very tough for me to be able to get any easier points.

"I don't take anything for granted. I think it would be quite obnoxious of me to come in here expecting I have a right to be in the second week."