NEW YORK: Naomi Osaka overcame a slow start to beat Czech Marie Bouzkova 6-4, 6-1 on Monday 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.
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.
She said she felt at home at Arthur Ashe Stadium, where she won her first major title three years ago.
Russian second seed Daniil Medvedev stayed solid from the baseline against Frenchman Richard Gasquet to advance to the second round with a 6-4, 6-3, 6-1 victory.
It was the 200th career win for the 25-year-old and his 160th on hard courts and the Russian showed why he is one of the top contenders for the title with a clinical display at Arthur Ashe Stadium in the final match of the opening day.
The 2019 US Open finalist, who also reached the title match of the Australian Open at the start of the year, broke Gasquet once in each of the first two sets before the veteran Frenchman seemed to start struggling physically.
Gasquet, 10 years older than his opponent, started to move gingerly in the third set in the hot and humid conditions at Flushing Meadows as Medvedev broke him three times to close out the match in under two hours.
World No 7 Andrey Rublev made short work of veteran qualifier Ivo Karlovic in the first round, beating the tricky Croatian 6-3, 7-6 (3), 6-3. Up next for Rublev is Spaniard Martinez who was made to work hard by Australian James Duckworth before sealing a 4-6, 4-6, 7-6(7), 6-2, 6-2 win.
Simona Halep, who missed three of the year's biggest events while recovering from a calf injury, delivered a statement win in her return to Grand Slam action as she beat Italian Camila Gorgi 6-4, 7-6(3).
The former world number one, who is seeded 12th in New York, relied on a solid serving game to get by in-form Gorgi, who won the biggest title of her career just two weeks ago in Montreal.
Halep missed the French Open, Wimbledon and Tokyo Olympics due to an injury suffered in Rome and then, in only her second tournament back, was forced to withdraw from a US Open tune-up event in Cincinnati due to a right thigh injury.
Nick Kyrgios spent more time battling chair umpire Carlos Bernardes than opponent Roberto Bautista Agut as the truculent Australian slumped to a 6-3, 6-4, 6-0 first round exit.
The furthest Kyrgios has gone at Flushing Meadows was the third round but the bad boy of tennis proved once again he can still pack in a crowd in New York as fans piled into Louis Armstrong Stadium hoping to see some late night fireworks.
The contest did not produce the explosive outbursts Kyrgios has become known for but there was no shortage of profanity laced rants as the Australian became embroiled in a standoff with Bernardes over where towels could and could not be placed on the court.
Taking his time to towel off after each point, the delays soon irritated Bautista Agut and the Spaniard expressed his frustration to Bernardes, who warned Kyrgios.
"My job is to come out here and entertain the people," roared Kyrgios. "Not to walk back and forth for a towel. I should be able to put the towel where I want. I don't want to walk back and forth, back and forth. How many extra steps is that? That's so stupid."
Wildcard Brandon Nakashima toppled fellow American John Isner 7-6 (7), 7-6 (6), 6-3 in the first round.
The 20-year-old tamed his 6'10" compatriot's fearsome serve, while Isner contributed to his own downfall with 28 unforced errors.
It was the second year in a row that Isner, the top-seeded American in the men's singles draw, exited in the first round at Flushing Meadows.
Former champion Sloane Stephens overcame best friend Madison Keys's aggressive play to secure a 6-3, 1-6, 7-6 (7) win.
The 2017 winner quickly took control of the first set on Arthur Ashe Stadium, putting up a strong defensive performance to fend off three break points as Keys committed 15 unforced errors.
Stephens faces fellow American Coco Gauff in the second round of the US Open.
Former champion Marin Cilic of Croatia retired from his first-round match against German Philipp Kohlschreiber with an apparent injury, his earliest exit from the US Open in 13 attempts.
The 2014 winner had been up two sets but bowed out of the match early on in the fifth with Kohlschreiber leading 2-0, after struggling with his serve.
It was Cilic's first retirement in more than 800 career matches and the first time he had failed to make it past the opening round at Flushing Meadows, as he joined American John Isner as one of the higher-profile players to exit the tournament on Monday.
Kohlschreiber next faces Spain's Pablo Andujar in the second round of the US Open.
Former finalist Kevin Anderson fired down 49 aces to defeat Czech Jiri Vesely 7-6 (1), 4-6, 3-6, 7-6 (5), 7-6(4) in the first round, stunning spectators at the US Open.
The 6'8" power server rattled off 17 aces in the final set alone, the last one coming on match point. The South African broke into wide grin in his moment of triumph before hoisting his arms aloft.
While his ace tally was well short of John Isner's record of 113, which he achieved during his 11-hour five-minute first-round win at Wimbledon in 2010, it nonetheless earned a standing ovation from the crowd packed into one of Flushing Meadows' outside courts.
Anderson, the runner-up in 2017, faces 11th seed Diego Schwartzman of Argentina in the second round. Agencies