No.1 seed Sofia Kenin of the US opened her season by beating Yang Zhaoxuan 7-6 (4), 6-2 in the first round of the Abu Dhabi Open on Thursday.

The American hit 11 aces against Yang to set up a second-round match against Kirsten Flipkens, who defeated Germany’s Laura Siegemund 5-7, 7-5, 6-4.

After a long pre-season, Kenin said she was happy to beat a player who had already had match practice in qualifying, but she had concerns about her own fatigue toward the end.

World No.4 Kenin, the 2020 WTA Player of the Year, needed over an hour to finally polish off the opening frame against Yang, a former Top 20 doubles player who is currently ranked World No.789 in singles and is contesting her first singles event since October of 2019. Kenin eventually took the straight-set victory after a total of one hour and 52 minutes of play.

Despite the loss, it was likely a heartening singles experience for 25-year-old Yang, who had won only two WTA main-draw singles matches in her career and had never before played a Top 30 opponent in the singles discipline.

Muguruza downs Mladenovic: No.5 seed Garbine Muguruza of Spain emerged the victor in an intriguing first-round battle as she defeated former Top 10 player Kristina Mladenovic of France 6-2, 6-4 in her first match of the season.

Former World No.1 Muguruza had lost two of her three previous meetings with Mladenovic, but the Spaniard had claimed a straight-set win in their most recent match, on the hardcourts of Monterrey in 2019. Muguruza is now level in her head-to-head record against Mladenovic after her 98-minute win this time around.

Two-time major champion Muguruza completed the match with 17 winners, five more than Mladenovic, and the Spaniard converted five of her 11 break points on the day.

Mladenovic could only go 2-for-10 on break points during the match, and was undone by 11 double faults, including five in the final game of the tilt.

The victory continues a run of recent good form for Muguruza in the Middle East. Muguruza made back-to-back quarterfinals in the region last year at Doha and Dubai, just weeks after her run to another major final at the 2020 Australian Open.

Mladenovic opened the match with a service break and a quick hold as the Frenchwoman leapt to a 2-0 lead, but that would be the extent of her winning ways in the first set, as Muguruza turned the opening frame around. The Spaniard saved a break point in the third game with a backhand winner down the line, eventually getting on the scoreboard with powerful play.

Having narrowly avoided going down a double-break, Muguruza started to wrest control of the set with pinpoint groundstrokes, and used an error-forcing return to get back on serve at 2-2. The Spaniard’s streak continued as she used a winning forehand down the line to earn another break point at 3-2, and she obtained the conversion for 4-2 after Mladenovic misfired on the volley.

A third break came Muguruza’s way to close out the set, after Mladenovic slammed her fifth double fault on the second set point she faced at 5-2, handing Muguruza a sixth straight game. After falling behind the early break, Muguruza converted three of her five break points to romp to the one-set lead.

Also, fourth-seeded Aryna Sabalenka came back after trailing 5-3 in the opening set to beat Polona Hercog 7-6 (5), 6-2, sixth-seeded Elena Rybakina defeated Lucrezia Stefanini 6-1, 6-3, Hsieh Su-Wei upset eighth-seeded Marketa Vondrousova 3-6, 6-3, 7-6 (3), and Sara Sorribes Tormo beat French Open semifinalist Nadia Podoroska 6-3, 6-3.

Mertens pulls out: Belgian Elise Mertens withdrew from the tournament on Thursday with a right shoulder injury hours before her opening match of the 2021 tennis season, the women’s governing body said.

The world number 20 was drawn to meet Cornet in her first round match in the season-opening event in the United Arab Emirates and will be replaced by Greek lucky loser Valentini Grammatikopoulou.

Mertens, 25, also pulled out from the doubles, in which she was to partner Belarusian Sabalenka, and would hope to regain fitness ahead of the Australian Open Grand Slam, which starts in Melbourne from Feb. 8.