New York - Rafael Nadal and Roger Federer will try to add another Grand Slam success in their age-defying seasons while Maria Sharapova takes her comeback to the highest stage when the US Open begins Monday.
World number one Nadal, back on top after more than three years, captured his 10th French Open in June for his 15th Grand Slam title while third-ranked Federer took the Australian Open and Wimbledon crowns, raising his record Slam total to 19.
"It's something that probably you and we don't expect to have that much success, but here we are," Nadal said. "And we worked well. We worked with passion and we played well. So let's see how we finish season."
Nadal, 31, and Federer, 36, have never faced each other on the New York hardcourts but could meet in the semi-finals.
"That would be fun for everybody involved," Federer said. "There's like 60-plus players in between us that don't agree we should make it to the semis. We have our work cut out there. I don't think we're both thinking that far ahead."
Federer opens against US teen Frances Tiafoe on Tuesday, the same day Nadal meets Serbian Dusan Lajovic in his first-round match.
"Ten victories to have that match. A lot of points and games to play," Nadal said of a possible semi-final with Federer. "Now is not the moment to think about that. For me, I think about Lajovic. That's my goal."
Nadal could face Bulgarian seventh seed Grigor Dimitrov, coming off his biggest career title two weeks ago at Cincinnati, in the quarter-finals while Federer's last-eight opponent could be Austrian sixth seed Dominic Thiem.
Until this year's revival, Federer had not won a Grand Slam title since Wimbledon in 2012. Nadal's most recent major crown was at Roland Garros in 2014.
"You could foresee maybe Rafa and me would be back in some shape or form but maybe not quite like this," Federer said. "I think we're all a bit surprised, all the players, all the media, all the experts and fans.
"It has been a great year and I hope we can keep playing like this."
For Sharapova, the Broadway stage shines a spotlight on her comeback and controversy. She served a 15-month ban after testing positive for the blood boosting drug meldonium at the 2016 Australian Open.
Her comeback began in April at Stuttgart, although many rivals were unhappy she was given wildcards into events. The French Open denied her a wildcard and she missed Wimbledon with a thigh injury.
Sharapova played only one US Open tuneup match before a forearm injury sidelined her, but she has practiced on the courts and taken inspiration from past success, notably a 2006 US Open title.
"Overall I think the inspiration is being here, really," Sharapova said in a video on the US Open website. "So many great memories of the tournament, being a champion, coming back to it."
The 30-year-old Russian has missed three of the past four US Opens, reaching the fourth round in 2014 in her most recent appearance.
Sharapova faces a difficult test Monday in the night feature match at Arthur Ashe Stadium against world number two Simona Halep of Romania.
But Sharapova is 6-0 lifetime against Halep, 10-0 in US Open first-round matches and has won 22 Grand Slam first-round matches in a row since the 2010 Australian Open.
"It's going to be a big challenge, first round of a Grand Slam, to face her," Halep said. "She beat me six times. Maybe I will change this. I just want to do my best to try to win and of course to enjoy it. It's a big match."
On the men's side, Germany's fourth-seeded Alexander Zverev faces Darian King of Barbados in his Grand Slam main draw debut while Croatian fifth seed Marin Cilic meets American Tennys Sandgren.
US 10th seed John Isner, the top-ranked player in his quarter of the draw thanks to a reshuffling when Britain's Andy Murray withdrew due to a hip injury, opens against France's Pierre-Hugues Herbert.