Two huge names in Rafael Nadal and Roger Federer are both on Sunday's schedule at the French Open in Paris, and tennis fans know that those two are on a collision course for the semifinal round if they can continue to roll at Roland-Garros.
Nadal has won the French Open 11 times, and he has beaten Federer in all five of their previous meetings in Paris. Nevertheless, that will be the most highly anticipated match of the tournament if both players continue to win.
That's probably a bigger issue for Federer, who is playing in the French Open for the first time in four years.
He is facing No. 68 Leonardo Mayer in the fourth round Sunday at 7 a.m. ET, and he is the fourth consecutive opponent Federer will face outside of the top 60 in the tournament.
While it still seems unlikely that the third-seeded Federer can find a way to beat Nadal or top-seeded Novak Djokovic on the red clay surface, the Swiss champion is thrilled with his play to this point in the tournament.
"A few months ago I didn't know what to expect," Federer said, per the Associated Press (h/t ESPN.com). "Now I know where my level is at. I still don't know exactly where my absolute best is, but I feel like it could be there.
"So I'm happy I'm putting myself in a position like this ... after not having played so many years here. The first goal has been reached by getting this deep into the tournament."
The second-seeded Nadal will attempt to advance to the quarterfinal round as he takes on unseeded Juan Ignacio Londero at 9:30 a.m.
While he continues to win in Paris, Nadal is coming off a four-set victory over 27th-seeded David Goffin. That result was somewhat surprising because Nadal dropped the third set of the match, and his relentlessness on clay usually leads to straight-set victories.
It marked the first time Nadal has lost a set in the first three rounds since 2013, per Rod Bodenburg of ESPN.com
However, it doesn't seem likely that Nadal will receive a major challenge from Londero, who was pushed to five sets in his third-round victory over unseeded Corentin Moutet.
Other key matches on the men's side includes sixth-seeded Stefanos Tsitsipas taking on No. 24 Stan Wawrinka at 9 a.m., along with seventh-seeded Kei Nishikori battling Frenchman Benoit Paire at 11:30 a.m.
Fourth-round women's matches include seventh-seeded Sloane Stephens competing against 19th-seeded Garbine Muguruza at noon, along with another match between two seeded opponents in No. 23 Donna Vekic and No. 26 Johanna Konta at 7 a.m.
Stephens opened the French Open with a pair of straight-set victories and then was pushed to the three-set limit by Polona Hercog in the third round. Stephens made it to the French Open championship round last year before falling to champion Simona Halep.
Muguruza struggled to a three-set win in her first-round match against Taylor Townsend before rolling to straight-set wins over Johanna Larsson and ninth-seeded Elina Svitolina. Muguruza's athleticism is likely to cause big problems for Stephens, and a three-set match appears likely.
Two other matches on the women's side include Marketa Vondrousova meeting 12th-seeded Anastasija Sevastova at 5 a.m., as well as 31st-seeded Petra Martic taking on unseeded Kaia Kanepi, also at 5 a.m. Martic upset second-seeded Karolina Pliskova in straight sets in her third-round match.
Federer is on an excellent roll in his return to Paris, and he has not lost a set to this point in the French Open. Look for another straight-set win against Mayer.
Nadal should have a similar victory in his match against Londero. Wawrinka has had a strong run to this point in the tournament and is capable of pushing Tsitsipas to the limit in the fourth round. However, Wawrinka's run will come to an end in the fifth set, as the 20-year-old Tsitsipas outlasts his opponent.
Paire will receive wonderful support from the French crown, but Nishikori will advance to the quarterfinals in four sets.
Muguruza will outlast Stephens on the women's side in three sets, while Vekic will need three sets to beat Konta. Martic and Sevastova will continue their winning ways in their fourth-round matches.