Miami, Mar 24 (IANS): Japan's Naomi Osaka delivered a composed and controlled performance to defeat Astra Sharma of Australia 6-3, 6-4 in the first round of the Miami Open, advancing in 1 hour and 20 minutes on Wednesday.

It was Osaka's 50th career WTA 1000 win, and sets up a second-round clash against another former World No.1, No.13 seed Angelique Kerber. Osaka claimed her first career Top 10 win over Kerber at the 2017 US Open, ending the German's title defence in the first round, but has lost all four of their subsequent matches.

Two weeks ago, Osaka had departed Indian Wells in tears after being rattled by a heckler during her 6-0, 6-4 second-round loss to Veronika Kudermetova. After her win over Sharma, she said she was keen to put that behind her.

"I didn't want to let anything bother me, no matter what happened," Osaka said. "The last match I played was not the greatest memory for me. I wanted to prove that I could come back out here and compete, and no matter if I won or lost, to just know that I had the best attitude I could."

Osaka was utterly dominant on serve, losing just two points behind her first delivery and six behind her second. And though her break point conversion rate was subpar as she took just two of her 11 opportunities, she did not let this frustrate her.

Having gained an early break in each set, Osaka was repeatedly stymied in her attempts to move up a double break. Sharma faced break points in every service game in the first set, but escaped 15-40 holes three times. In the second set, the Australian also escaped three match points while serving to stay in the match.

But Osaka responded to all of these missed chances by simply posting rapid-fire service holds to maintain her advantage. Sharma managed to come up with two of the best shots of the match in the second set, a pair of remarkable forehand gets, but in the main it was Osaka who had the edge in terms of power and angles in baseline rallies.