NEW YORK (CBSNewYork/AP) — Two-time US Open runner-up Caroline Wozniacki rallied from a set down for her first Grand Slam match win of 2016.

Wozniacki beat American qualifier Taylor Townsend 4-6, 6-3, 6-4 on Monday in the first-ever match at the new 8,000-seat Grandstand at the Open. She lost in the first round at this year’s Australian Open and Wimbledon and skipped the French Open because of a right ankle injury that forced her to miss 2½ months. The former No. 1-ranked player has slipped to 74th, and she’s unseeded at Flushing Meadows for the first time since her debut in 2007.

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The 20-year-old Townsend, ranked 146th, was playing her second US Open.

Meanwhile, Australian Open champ Angelique Kerber advanced to the second round when her opponent retired early in the second set without winning a game.

The second-seeded Kerber led 6-0, 1-0 after 33 minutes when Polona Hercog stopped. The 120th-ranked Slovenian won just nine points in seven games.

After the first set on a 90-degree day, Hercog took a medical timeout. Trainers checked her blood pressure and rubbed ice bags on her legs.

Eearlier Monday, Roberta Vinci of Italy, who stunned Serena Williams en route to reaching last year’s US Open final, won the first match in the tournament’s refurbished Arthur Ashe Stadium.

Vinci, who is seeded No. 7, overcame some second-set jitters to beat 46th-ranked Anna-Lena Friedsam of Germany 6-2, 6-4 on Monday.

In the 2015 semifinals at Flushing Meadows, Vinci — unseeded and ranked 43rd at the time — upset Williams, ending the American’s bid for tennis’ first calendar-year Grand Slam in 27 years. That put Vinci into her first major final, where she lost to another Italian, childhood friend Flavia Pennetta.

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On the men’s side, Kyle Edmund, making his Open debut, upset 13th-seeded Richard Gasquet.

The 21-year-old Brit won 6-2, 6-2, 6-3 against the 2013 US Open semifinalist. Edmund, ranked 84th, had 40 winners, 21 on his forehand. He has twice made it to the second round at the French Open.

Gasquet hadn’t lost in the first round at a major since 2010 at Roland Garros.

“Not sure I could do worse,” Gasquet said.

The new retractable roof atop Ashe provided some shade from the sun for spectators — and, on one side of the court, players.

The $150 million roof, which can close in about seven minutes, is to be used, according to tournament officials, only “in the event of inclement weather or the strong possibility of inclement weather.”

Neither is expected in the next few days, with forecasts calling for clear skies and highs in the 80s.

The roof is still set to make its debut, of sorts, at Monday night’s opening ceremony. The U.S. Tennis Association plans to shut the roof after the day session and open it for effect while Phil Collins performs “In the Air Tonight.”

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