[gallery size="medium" td_select_gallery_slide="slide" td_gallery_title_input="Halep wins under roof to reach third round at US Open" ids="81644,81646,81645"] NEW YORK — Romanian fifth seed Simona Halep advanced to the third round of the US Open with a 6-3, 6-4 win over Lucie Safarova Thursday in the first full match played under a closed roof at Arthur Ashe Stadium. The $150 million retractable roof was installed ahead of this year's tournament and guaranteed there would be at least some action on a muggy and overcast Day Four at the year's final grand slam. "It was a little bit (of an adjustment)," Halep said about playing under the roof. "But I had the chance to warm up in the morning before the match. "I don't want to say anything bad because it wasn't bad. Had a nice feeling. "It was a great experience to be there. I didn't have to wait for the rain, so that's a good thing." The roof, which has been a huge source of fascination for the Flushing Meadows crowds, was first used Wednesday when it was put into action in the middle of Rafa Nadal's second-round victory over Andreas Seppi. On a midweek morning session with the roof closed and a sparse crowd sprinkled through the massive stadium, Arthur Ashe had a vacuous, sterile atmosphere. But more importantly, with rain delaying action on the other courts, play went ahead as scheduled on the main court where Halep needed 88 minutes to dismiss an error-prone Safarova, a two-time Grand Slam doubles champion, who committed a whopping 44 unforced errors. On Wednesday, French Open champion Garbine Muguruza and Wimbledon runner-up Milos Raonic crashed out of the US Open. Third seeded Spaniard Muguruza, who has struggled in the aftermath of her Roland Garros breakthrough in June, slumped to a 7-5, 6-4 loss to Latvia's Anastasija Sevastova, the world No. 48. A horribly out of sorts Muguruza rallied from 1-5 down in the second set, saving three match points, but Sevastova, who briefly quit the sport in 2013, held her nerve for the victory. Having not won a match at the US Open in five years before this week, 26-year-old Sevastova now goes on to face Kateryna Bondarenko, a 5-7, 7-6 (7/5), 7-5 winner in three hours over China's Zheng Saisai. "This is why I came back to the sport for the big stages like this and night sessions at the Slams. But I was shaking a little at the end," she said. Muguruza admitted she had been outplayed. "It was a very tough match. I think I didn't play well. Everything she was doing was working," said the 22-year-old who has never made the third round in New York. Meanwhile, 120th-ranked Ryan Harrison of the United States stunned fifth seeded Raonic 6-7 (4/7), 7-5, 7-5, 6-1 in another second round upset. "It was extremely physical out there. I was playing on adrenaline," said 24-year-old qualifier Harrison who was as high as 43 in the world in 2012. He goes on to face experienced Cypriot Marcos Baghdatis for a place in the last 16. Baghdatis eliminated 32nd-seeded Benoit Paire of France 6-2, 6-4, 3-6, 6-4. Harrison has now reached the third round of a Slam for the first time after recording just a second win over a top 10 opponent in 27 meetings. Raonic, considered as a potential title dangerman in New York, hit 69 winners but committed 62 unforced errors. "I started cramping midway through the second set. There was a lot of nerves and stress. It was a result of over-exuberance," said 25-year-old Raonic. Nadal, the 2010 and 2013 champion, eased past Italy's Andreas Seppi 6-0, 7-5, 6-1 in a match which became the first to be completed under the new retractable roof on Ashe. Light rain caused the structure to be closed at 3-3 in the second set with play only held up for around seven minutes. Nadal beat Seppi for the eighth time in nine matches and next faces Russia's Andrey Kuznetsov. World No. 1 Novak Djokovic made the last 32 of a major for the 33rd successive time without hitting a ball when Jiri Vesely of the Czech Republic withdrew from their second round encounter suffering an inflammation of the left forearm. Djokovic will face 34-year-old Russian Mikhail Youzhny, twice a semifinalist, Friday for a place in the last 16. Britain's Johanna Konta, the 13th seed, collapsed on court with heat sickness before completing a 6-2, 5-7, 6-2 win over Bulgaria's Tsvetana Pironkova. After a medical timeout, the Briton dropped the second set before heading off on a lengthy toilet break which did little to help her opponent's composure in the decider. "I'm a little embarrassed. I'm not a fan of drama. I did the best that I could with the cards that I had," said Konta. Angelique Kerber, the second seeded Australian Open champion, made the last 32 by seeing off 34-year-old Mirjana Lucic-Baroni of Croatia 6-2, 7-6 (9/7). Kerber faces 17-year-old CiCi Bellis of the United States, for a place in the last 16. Denmark's Caroline Wozniacki upset 2004 champion Svetlana Kuznetsova of Russia 6-4, 6-4. Croatian seventh seed Marin Cilic, the 2014 champion, made the last 32 by seeing off Sergiy Stakhovsky 6-1, 6-2, 6-3. A couple of Americans moved into the third round — No. 20 John Isner beat Steve Darcis 6-3, 6-4, 6-7 (10), 6-3, and No. 26 Jack Sock defeated Mischa Zverev 6-1, 6-1, 6-2. Kevin Anderson of South Africa recorded a 7-6 (7/3), 6-4, 6-4 victory over Canadian Vasek Pospisil.
