Naomi Osaka overcame a slow start to beat Czech Marie Bouzkova 6-4 6-1 as the world number three got her US Open title defence under way in front of a roaring capacity crowd.

Unseeded Bouzkova held her own through much of the first set but failed to convert on four break point opportunities against the Japanese four-time Grand Slam winner.

Osaka, who fired 21 winners but committed 13 unforced errors in the first set, broke Bouzkova’s serve at 5-4 to win the opener and never looked back, winning the first five games of the second despite struggling with her first serve.

She closed out the match with a forehand winner, offering a smile and a wave to the stands that were empty a year ago.

“It feels kind of crazy to play in front of everyone again,” said Osaka.

“Last year when we didn’t have a crowd I know it felt quite lonely for me.”

The evening marked a reassuring return to form for Osaka, who crashed out in the third round of the Tokyo Olympics and the Western & Southern Open.

Halep’s winning return

Simona Halep, who missed three of the year’s biggest events while recovering from injury, delivered a statement win on her return to Grand Slam action when she beat Italian Camila Giorgi 6-4 7-6(3).

The former world number one, seeded 12th in New York, relied on a solid serving game to get by the in-form Giorgi, who won the biggest title of her career two weeks ago in Montreal.

Halep twice failed to serve out the win but the Romanian, staring at the possibility of having to play a decider, regained control of the match and breezed through the tiebreak.

Halep missed the French Open, Wimbledon and the Tokyo Olympics due to an injury, was forced to withdraw from a U.S. Open tune-up event in Cincinnati due to a right thigh injury.

The 29-year-old Romanian was considered to be one of the more vulnerable seeds in New York but showed she was up for the task at hand in the day’s first match on Grandstand.

Halep, a two-times Grand Slam champion whose best US Open finish came in 2015 when she reached the semi-finals, won 83% of her first-serve points, fired down six aces and faced just two break points during the 93-minute match.

Next up for Halep will be Slovakian lucky loser Kristina Kucova. PHOTO/COURTESY

REUTERS