Australian tennis diva Daria Gavrilova is plotting the first major upset of the US Open, convinced she can topple five-time grand slam champion Maria Sharapova for the second time this year.

Gavrilova takes on her former Russian compatriot in one of the feature women’s matches on the opening day of at Flushing Meadows on Monday.

And far from daunted, Gavrilova is relishing a showcourt duel with the third seed after her stunning victory over Sharapova on a similarly fast American hard court in March sparked the 21-year-old’s dramatic rankings surge.

“I’m just going to get out there and do the same thing as I did in Miami. I executed pretty well so hopefully I’m going to do it again,” Gavrilova said on Saturday.

“I’m pretty positive. I’m pretty lucky I get to play Maria first round, where some players need to win a few matches to get to play someone like her.

“Obviously I did it once, so I’m pretty confident I can do it again. It’s not easy, but I’m looking forward to it. I’m really excited to playing on a big court.”

With wins over Australian No.1 and former US Open champion Samantha Stosur, French Open runner-up Lucie Safarova and former French Open finalist Sara Errani in the past month, Gavrilova almost nabbed a seeding at Flushing Meadows.

“I had a good US Open series,” said the world No.37 with a bullet.

“I played a few top-10 players and lots of good players and I think I’m playing pretty well and I’m confident.”

Sharapova enters the final slam of the year under a fitness cloud after withdrawing from last week’s Cincinnati Masters with a leg muscle strain.

“I’ve done everything I could to be ready,” she said on Saturday.

“There’s nothing more that I could have done so, yeah, I hope to be ready.

“Obviously she (Gavrilova) is a really great player and a tough first round.

“We’ve gone back and forth with our results this year. She beat me in Miami and I had a good win against her in Rome so she’s a really good opponent.”

Casey Dellacqua also launches her campaign on Monday.

With a load of rankings points to defend after making the fourth round last year, Dellacqua isn’t taking Estonian qualifier Anett Kontaveit lightly.

“She’s had three matches here; you never take qualifiers lightly because they’re confident,” the West Australian said.

“I have played her and I know what to expect and that’s going to be a really tough match. She’s a really good competitor.

“I have to be on my game and really sharp and really ready to go.”