Carlos Alcaraz and Aryna Sabalenka facing tricky American tests at US Open

The Spaniard, playing his first tournament since a four-month absence with a wrist injury, acknowledges he has yet to play his best but says he's "getting there" with both the sharpness of his shots and his on-court decision-making.

He headlines a day that also features women's two-time defending champion Aryna Sabalenka and third-ranked American Jessica Pegula -- just one of the players with a chance to supplant Sabalenka atop the world rankings in New York.

Surprise Wimbledon champion Linda Noskova will try to continue her progress toward another Grand Slam against dangerous Ukrainian Marta Kostyuk, while US hope Frances Tiafoe faces the always tricky former champion, Daniil Medvedev.

AFP Sport looks at three matches to watch on Day 8 of the US Open:

Carlos Alcaraz vs Tommy Paul (6-2)

Although Alcaraz has dominated their meetings -- Paul's last win over the Spaniard was back in 2023 -- the defending champion said the American is "really dangerous for everyone on the tour.

"The way he plays, the way he hits the ball, it's really complicated to dominate the ball, dominate the points," said Alcaraz, who won their last meeting in the Australian Open quarter-finals on the way to the title that made him the youngest man to claim a career Grand Slam.

Alcaraz said he was looking forward to another great battle -- and having some fun.

"We pull off great points, great shots," he said. "It's going to be really fun to watch, fun to play, as well."

Ben Shelton vs Stefanos Tsitsipas (0-1)

A resurgent Tsitsipas has Shelton's attention. The former top-five player from Greece upset red-hot Arthur Fils in the first round and ousted 18th-seeded Jiri Lehecka in the third and is deeper into a Grand Slam than he's been in more than two years.

Playing pain-free after back problems derailed his 2025 campaign, the two-time Grand Slam finalist is also working with a new coach, having replaced his father Apostolos in that role.

"I have been watching his matches," Shelton said. "I think he's playing great. I think that his style of tennis can be very, very effective on all surfaces, all-court game, great athlete."

Shelton said his three four-set wins in the first three rounds -- against Tallon Griekspoor, Hubert Hurkacz and Denis Shapovalov -- had him well prepared for anything Tsitsipas might throw at him.

"I think this is a great way to start the tournament in terms of variety. I have dealt with a lefty, dealt with a big hitter, dealt with a feel guy, dealt with a massive server, dealt with a spot server, serve and volleyer."

Aryna Sabalenka v Taylor Townsend (First meeting)

Sabalenka knows she'll be in hostile territory when she takes on 96th-ranked American Townsend on Arthur Ashe Stadium.

"I think I'm ready for the crowd situation," Sabalenka said. "She's, I'd say, tricky player, because she brings the variety -- comes to the net, really make you think during the game."

Townsend is in the fourth round for a second straight year, but it has been anything but a straightforward 12 months for the 30-year-old, who says she has "been through a lot over this past year."

It hasn't dimmed her desire to win, and Townsend said she was "pumped" to take on Sabalenka in a quest for a first Grand Slam singles quarter-final.

"I'm built for these moments," Townsend, a three-time Grand Slam doubles winner, said. "I'm ready to take it. I'm ready to go."