US Open Day 4 - three matches to watch

Roger Federer celebrates his first round win over Yoshihito Nishioka

Three matches to watch on Thursday, the fourth day of the US Open (x denotes seeding):

Roger Federer (x2) v Benoit Paire (FRA)

Federer, seeking a first US Open title since winning the last of his five straight at Flushing Meadows in 2008, boasts a dominant record against mercurial Frenchman Paire, winning their first five meetings in straight sets.

But Paire pushed the Swiss great to the brink in Halle this year, forcing two match points that he failed to convert in a three-set defeat.

If Federer, who made short work of Yoshihito Nishioka in the first round, gets the job done in the afternoon heat on Arthur Ashe Stadium he could book a third-round meeting with Nick Kyrgios -- if the dangerous Australian gets past France's Pierre-Hugues Herbert.

Novak Djokovic (SRB x6) v Tennys Sandgren (USA)

Djokovic demolished Sandgren 6-3, 6-1, 6-2 in the first round at Wimbledon on his way to a 13th Grand Slam title.

The 27-year-old American will be hoping to put up more of a fight under the Ashe Stadium lights, but with Djokovic in his path he'll be hard-pressed to emulate his run to the Australian Open quarter-finals. There his star-making turn was somewhat overshadowed by backlash over alt-right ties on his Twitter account and the scrutiny prompting the American's scathing indictment of the media after his quarter-final defeat.

Vera Zvonareva (RUS) v Aryna Sabalenka (BLR x26)

Sabalenka, 20, is seeded at a Grand Slam for the first time as she aims to continue the red-hot form that saw her capture a first WTA title in New Haven on the eve of the US Open.

After a gritty first round win over Danielle collins the rising star will face 2010 runner-up Vera Zvonareva, a 33-year-old former world number two on the comeback trail. Zvonareva came through qualifying and won her first main draw match at the tournament since 2011 when she beat fellow Russian Anna Blinkova in three sets on Tuesday.