After a shaky start the much-maligned Naomi Osaka opened her US Open title defense with a much-needed 6-4, 6-7(5), 6-2 win over 20-year-old Russian Anna Blinkova.

The 21-year-old Osaka fell quickly behind 4-1 before coming back to take the first. In the second, despite continued to spray errors, the World No. 1 reached match point but couldn’t finish. After losing a nervous breaker, Osaka pulled away in the third for her 8th straight win in New York.

“I don’t think I’ve ever been so nervous in my life,” Osaka told the crowd. “I don’t think I ever really found my rhythm, but I just fought as hard as I can.”

Later in the day, No. 4 seed Simona Halep also went the distance in a three-set win over American 26-year-old Nicole Gibbs 6-3, 3-6, 6-2. Gibbs, a “lucky loser”, made things interesting in the second before Halep simply outplayed the former Stanford standout in the third.

The story from the women’s draw, Coco Gauff, made her US Open debut Tuesday, and once again she lit up the event. The 15-year-old was in a fight with 18-year-old Anastasia Potapova and early on the Russian was hammering winners off both sides.

But in the second the winners slowly turned into errors and the Armstrong crowd lifted Gauff to force a third.

Both continue to hit errors but Potapova was a mess quickly going down 4-1. After a medical timeout for a shoulder, Potapova got back on track and leveled, but Gauff was too strong scoring the 3-6, 6-2, 6-4.

“It was crazy,” said Gauff. “Obviously I was nervous going out on the court. It’s such a big court. Then my home slam, so I wanted to do well. The crowd really helped me the whole match. Like, it was really a great atmosphere to play in and a great experience for me.

“I think it was a good match on such a big stage so a lot of people could see it,” she added. “She’s young, too. She’s only a couple years older than me. I know we’re going to see each other a lot in the future. I hope we do see each other in the future, but hopefully in the finals, not in the first round.”

Also on Armstrong, in the first-ever battle between two Bela-Russian women, Aryna Sabalenka took down 2-time US Open finalist Victoria Azarenka 3-6, 6-3, 6-4.

Caroline Wozniacki and Bianca Andreescu were also winners while 2017 champion Sloane Stephens was stunned by Russian qualifier Alina Kalinskaya 6-3, 6-4.

Alison Riske also knocked out the slumping Garbine Muguruza in three sets.

After a dominant first round showing on Monday, former champions Serena and Williams return. Venus will meet the much-higher ranked Elina Svitolina in the match of the day in the women’s draw.

Former finalists Karolina Pliskova and Madison Keys are also featured. Ashleigh Barty is action against Lauren Davis.