U.S. Open 2019: How to Watch Coco Gauff, Rafael Nadal First Round Matches, Start times, Live Stream

Two of men's tennis's big three and Serena Williams all safely progressed through to the second round of the U.S. Open on Monday.

World number one Novak Djokovic began the defense of his title with a 6-4, 6-1, 6-4 win over Spaniard Roberto Carballes Baena, while Roger Federer beat Indian qualifier Sumit Nagal in four sets.

The Swiss, a five-time winner in New York City, lost the opening set 6-4 before recovering to win the next three sets 6-1, 6-2, 6-4.

In the women's tournament, meanwhile, Serena Williams kicked off her quest for a 24th Grand Slam singles title with a dominant win over Maria Sharapova.

It took the number eight seed just 59 minutes to beat the Russian 6-1, 6-1, winning her 19th consecutive match against Sharapova and taking her record to 20-2 in one of the most famous and heated rivalries of modern tennis.

"Every time I come up against her, I just bring out some of my best tennis,'' Williams told reporters after the game.

Williams has had a difficult time with injuries of late but dismissed any concerns over her fitness.

"The body's good. I feel good,'' she added. "My back's a lot better. So I'm excited. This is going to be fun.''

Rafael Nadal and women's world number one Naomi Osaka are among those in action in the first round on Tuesday, along with tennis's teenage sensation Coco Gauff.

A three-time U.S. Open champion, Nadal is the number two seed in the men's draw and takes on Australia's John Millman at 7 p.m. ET

Osaka, the defending champion, begins her title defense at 12 p.m. ET against Russia's Anna Blinkova, who reached the quarterfinal at last week's Bronx event.

Gauff, who emerged as tennis's latest rising star when she reached the round of 16 at Wimbledon, will take on Anastasia Potapova of Russia.

Here's everything you need to know to keep up with the action on Tuesday.

Rafael Nadal, US Open
Rafael Nadal of Spain practices with coaches, Carlos Moya and Francisco Roig, on Arthur Ashe Stadium at the USTA Billie Jean King National Tennis Center on August 25 in New York City. TPN/Getty

First round start time

Action begins at 11 a.m. ET, with 15 matches on the schedule. Play at the Arthur Ashe doesn't begin until 12 p.m., when Naomi Osaka takes on Anna Blinkova, while Rafael Nadal opens the evening session at 7 p.m.

Coco Gauff will not be in action before 3 p.m. at the Louis Armstrong Stadium, with her match following the game between number four seed Simona Halep and Nicole Gibbs.

TV channel

The tournament is broadcast exclusively across ESPN channels, with coverage beginning at 11 a.m. and running until 11 p.m. ET on Tuesday on both ESPN and ESPN+.

Live stream

Fans can watch the action online via the WatchESPN app and on ESPN.com.

First round full schedule

Former US Open champions Sloane Stephens, Marin Cilic, and Svetlana Kuznetsova are all in action on Tuesday, along with rising stars Stefanos Tsitsipas, Dominic Thiem and Belinda Bencic.

Australia firebrand Nick Kyrgios, former world number one Caroline Wozniacki and two-time Wimbledon winner Petra Kvitova are also all scheduled to play in the first round.

Aside from Gauff and Gibbs, there's a number of Americans on show on Tuesday.

Alison Riske takes on Spain's Gabrine Muguruza, before number 14 seed John Isner plays her compatriot Guillermo Garcia-Lopez.

Tennys Sandgren and Kristie Ahn, meanwhile, play Jo-Wilfried Tsonga and Russia's Svetlana Kuznetsova.

The full schedule is available here.

Odds

According to Oddschecker, Novak Djokovic is a 6/5 (+120 in moneyline terms) favorite to win the tournament, followed by Rafael Nadal and Roger Federer at 3/1 and 15/2 respectively.

In the women's tournament, Serena Williams is a 5/1 favorite, followed by Simona Halep at 15/2 and world number two Ashleigh Barty at 9/1.

U.S. Open 2019: How to Watch Coco Gauff, Rafael Nadal First Round Matches, Start times, Live Stream | Sports