(REUTERS) - Rafael Nadal beat Alexandr Dolgopolov 6-3, 6-3 in the Brisbane International first round on Tuesday (Jan 3), to make a successful return to tennis action after 21/2 months out owing to injury.

The Spanish former world No. 1, seeded fifth, made a sluggish start and fell 1-3 down in the first set against his Ukrainian opponent.

But Nadal, 30, won four successive games to clinch the opening set and the 14-time Grand Slam winner broke twice in the second to see off 2012 Brisbane finalist Dolgopolov in one hour 15 minutes. He will next play Germany's Mischa Zverev.

In the women's draw, Spanish fourth seed Garbine Muguruza saved a match point before beating 19-year-old Russian Daria Kasatkina 7-5, 3-6 ,7-6 (9-7) to reach the last eight, where she will face Destanee Aiava or twice Grand Slam champion Svetlana Kuznetsova.

Australian 16-year-old Aiava upset American Bethanie Mattek-Sands 2-6, 6-3, 6-4 to become the first player born in or after year 2000 to win a WTA main draw match.

World No. 6 Karolina Pliskova crushed American qualifier Asia Muhammad 6-1, 6-4 to set up a quarter-final meeting with eighth seed Roberta Vinci or Japan's Misaki Doi.