Kim Clijsters, who has retired from tennis twice, announced that she would be coming out of retirement for the second time. Last September Clijsters promised that she would return to the courts in 2020, after eight years of absence.

The 36-year-old faced GarbiñeMuguruza in the first round of the WTA Dubai Tennis Championships and lost in two sets, 6-2, 7-6 (6) in an hour and 37 minutes. Clijsters showed flashes of brilliance, particularly in the second set. “She’s back, and she’s an incredible player,”Muguruza said in her on-court interview.

“It was a special match. I didn’t know how it was going to go, but I’m happy to be the one to play her, and I think she gave me a really hard time today,”Muguruza said. “A player who’s played incredible can play incredible again, so I expected it was going to be hard. I just tried to stay calm and keep doing my game, and hoping it was going to go my way.”

Serena Williams voiced her support of Clijsters’s superb performance against a top competitor. “Seriously so soso proud of Kim Clijsters. You inspire me. Wow. Just wow congrats you did amazing,” Williams tweeted.

Clijsters had originally scheduled her comeback in January at the Australian Open but a knee injury forced her to make new plans. The former world No. 1 then announced that her first tournament would be in Mexico in March but she preferred to have her anticipated return in the hard surface courts of Dubai.

The Belgian tennis star first took a break from the sport in 2007. She returned to competition in 2009, after her first child Jada was born. She has 41 titles, including four Grand Slams (the US Open in 2005, 2009 and 2010 and the Australian Open in 2011).