NEW YORK (AP) -- Ranked second in the world, Simona Halep merited the honor of kicking off the U.S. Open on center court.
The stage proved imposing at first, and Halep needed to rally from a set down to beat a young American making her Grand Slam debut.
The Romanian won 6-7 (2), 6-1, 6-2 on Monday over 20-year-old Danielle Rose Collins. As a sophomore at Virginia, an unseeded Collins won the NCAA title to earn a wild card into the U.S. Open.
The French Open runner-up, Halep reached a career-high ranking of No. 2 this month. She has never advanced past the fourth round at the U.S. Open.
"My best moment of my life - I have to enjoy this," she said in an on-court interview after the match. "But it's not easy. There's a lot of pressure on me. Everyone is telling me that I have chances to win."
For Collins, she expected to return 24 hours later to a far smaller venue: a college classroom.
"Summer was too much fun," she said.
Hobbled by injuries during the season, Collins rolled through the NCAA tournament to become the Cavaliers' first women's singles champion in May.
She had never before even played a main draw match at a tour-level event. She started right at the top by playing in Ashe.
"It was amazing," Collins said. "I mean, I could get used to that."
Ranked 47th at the end of 2012, Halep's rapid rise booked her as the opening act in the cavernous confines of Arthur Ashe Stadium. Her reaction when she found out: "Wow."
"It's not easy to see that you play first match of tournament on center court," she said. "But, you know, I have experience now. I didn't manage very well the emotions, but it's good that I finished well."
Sixth-seeded Angelique Kerber also needed three sets to outlast qualifier Ksenia Pervak 6-2, 3-6, 7-5, coming back from down a break in the third set.
Fourth-seeded Agnieszka Radwanska had no such trouble. She beat Sharon Fichman 6-1, 6-0 in 47 minutes, losing just three points in the second set.
-- Rachel Cohen, AP NEWS