The second round of the US Open began with the top half of the women's draw in action. Two matches weren't played as third seed Naomi Osaka received a walkover from qualifier Olga Danilovic while 16th seed Angelique Kerber and Anhelina Kalinina saw their match pushed back to Thursday.
Second round results
Sabalenka dominated Tamara Zidansek 6-3, 6-1 as she needed 59 minutes to notch her 40th match win of the season. The second seed played a clean match, striking 23 winners while committing just 10 unforced errors against the Roland Garros semifinalist.
"I think it was a really solid match, and I did everything I could in this match", she told the press. "I'm really happy with this win. I think it was a great level for me today."
26th seed Danielle Collins will be Sabalenka's third-round opponent after dismissing another Slovenian Kaja Juvan 6-4, 6-2 in just 69 minutes.
"[Collins is] a great player", Sabalenka said. "We had a couple matches against each other, and it was tough matches. She's playing well right now, moving much better than she was before.
"She's, I would say, a powerful player, and she can come back whenever she wants to."
Svitolina continued her impressive play, defeating Spanish qualifier Rebeka Masarova 6-2, 7-5 for her seventh consecutive victory dating back to last week when she won the Chicago title.
The Ukrainian hit 22 winners and never faced break point in the one hour, 15 minute match against the 231st-ranked Masarova, which included a 30-minute rain delay at 5-5 in the second set.
25th seed Daria Kasatkina continued her resurgent season with by edging Olympic silver medalist Marketa Vondrousova 3-6, 6-4, 6-4 in two hours, 17 minutes. The Russian next challenges Svitolina, whom she is 0-5 against lifetime.
Krejcikova had little trouble defeating Christina McHale 6-3, 6-1 with the match starting on Court 13 and the Czech taking a 6-3, 2-1 lead before light sprinkles turned into a torrential downpour. About 30 minutes later, the match restarted under the roof of Louis Armstrong Stadium.
The change in venue did little to bother the reigning Roland Garros champion as she reeled off the four games played at Armstrong to close out her 12th win in her last 13 major matches.
"I wasn't happy when it started to rain, but when I heard that they moved us I was really happy because I love to play on a big court and on the big stages", Krejcikova said.
"I wish in the future I will be playing more matches like this on the big courts, playing big players, that i'll be able to compete at the highest level to entertain people."
Next up for Krejcikova will be Russian lucky loser Kamilla Rakhimova, who upset 32nd seed Ekaterina Alexandrova 6-4, 6-1, in just over an hour. World No.115 Rakhimova became just the fourth lucky loser in the Open era to reach the third round in New York.
Muguruza fought past veteran Andrea Petkovic 6-4, 6-2, hitting 21 winners while only committing 14 unforced errors. The Spaniard converted on six of her ten break chances and equals her best showing in New York.
"Andrea and I, we have spent so many times, so many hours on court together", Muguruza told the press, after her win. "We know each other a lot. [She is] one of the nicest people on tour.
"I just felt that it was difficult at some point to play, because, you get along well, but happy with my level. I think I played a very solid match from the beginning until the end."
The two-time major champion will face another two-time Slam champion in 18th seed Victoria Azarenka, who got past Italian Jasmine Paolini 6-3, 7-6 (1).
Last year's finalist was perfect at the net, winning all 15 of her points when coming forward and has won eight of her last nine matches at Flushing Meadows.
"I thought it was a pretty good level, especially the first set", Azarenka said, after her win. "I felt that in the second set I had some opportunities that I didn't close out, but she played a couple of pretty flashy moments.
"Overall, I thought it was a pretty high-quality match, and I felt that I was happy that in the end I closed out in a strong way."
12th seed Simona Halep sped into the third round, winning nine of the final ten games against lucky loser Kristina Kucova by a 6-3, 6-1 scoreline in just 68 minutes.
After Danilovic withdrew against Osaka, the Romanian saw her match moved from Court 17 to Arthur Ashe Stadium, ensuring she would get it done.
The two-time major champion opened up about her struggles with a calf tear that kept her sidelined for three months that forced her to skip the French Open, Wimbledon and the Olympics.
"At the beginning [it] was very tough. Because [this] never happened to me, this kind of injury, to have a muscle brojen in two spots, big spots. So it was challenging, because I never faced something like this before.
"And now I feel happy that I feel good, no pain, no struggling with the mental part. So i'm just happy to be on court and trying my best to win every match I play."
Halep's next opponent will be 19th seed Elena Rybakina as the Kazakh swiftly dismissed Caroline Garcia 6-1, 6-4. This is her first appearance in the third round of the US Open.
20th seed Ons Jabeur blew away Maria Camila Osorio Serrano 6-0, 6-1 in 53 minutes, firing off 16 winners and winning eight of eight points at net against the Colombian, who was making her main draw debut.
Next up for the Tunisian is 15th seed Elise Mertens as the Tunisian saw off Greek qualifier Valentini Grammatikopoulou 6-2, 6-2. The Belgian was a game away from victory when the rain came and returned to clinch the win on her second match point.
Stephens produced a dominant display in ousting Gauff in just 66 minutes in what was the highest-profile second round match. The 2017 champion won eight of the final ten games to reach the third round for the second consecutive year.
She held to love in five of her nine service games, served at 84 percent for the match and lost just ten total points on her delivery as she awaits Kerber or Kalinina, who will play today.
"I've had to battle two good friends", Stephens said. "I think the pressure is a little bit different when you play two people that you know well. It's a different type of pressure.
"I'm really happy with the two wins. I played good tennis to get them. It's still only the third round of a Slam so I have to keep going. But it's nice to know that I was able to get those two wins with all the pressure and outer things happening."
Leylah Fernandez defeated Kaia Kanepi 7-5, 7-5 to reach the third round of a major for the second time, where she will face Osaka.