NEW YORK: Naoimi Osaka of Japan hits the ball against Anna Blinkova of Russia during the Round One Women's Singles match at the 2019 US Open at the USTA Billie Jean King National Tennis Center in New York. - AFP

NEW YORK:Reigning US Open champion Naomi Osaka confronted severe nerves in a rocky startto her title defense Tuesday while men's contenders Dominic Thiem and StefanosTsitsipas tumbled out in the first round. Osaka suffered a first-round exitlast month at Wimbledon and the Japanese star struggled to put away Russia'sAnna Blinkova in her opener at Arthur Ashe Stadium before prevailing 6-4, 6-7(5/7), 6-2.

"I have alot of really good memories here because I grew up in this area. I don't thinkI've ever been this nervous in my life," said Osaka, sporting a blackbrace on the left knee that prompted her to retire in Cincinnati.

"You want todo well after you did well last year. I definitely didn't want to lose in thethird set." The top seed goes on to face Poland's Magda Linette, whocaptured her maiden WTA title in the Bronx last week.

Osaka must retainher Flushing Meadows crown to have a chance of remaining world number one andwas tested extensively by 2015 Wimbledon junior finalist Blinkova, who raced4-1 ahead in the first set and saved a match point in the second to force adecider. "I knew it was going to be a really tough battle. The only thingI would have wished is that I won the first match point," Osaka said.Two-time French Open runner-up Dominic Thiem was upset by Italian giant-killerThomas Fabbiano 6-4, 3-6, 6-3, 6-2 as three top-10 players were eliminated fromRafael Nadal's half of the draw.

"I got verytired and exhausted after two sets. I'm far away from 100 percent," Thiemsaid. "It was not the real me there on the court." Greek eighth seedTsitsipas struggled with cramps and accused umpires of having"preferences" after he slumped to a 6-4, 6-7 (5/7), 7-6 (9/7), 7-5defeat by Next Gen rival Andrey Rublev in a gruelling four-hour slog. LikeThiem, it was a second successive Grand Slam first-round exit for Tsitsipas,who was hit with a point penalty in the final set for a time violation.

"This chairumpire, I don't know, he has something against me. I don't know why," saidTsitsipas, who snapped "you're all weirdos" at French official DamienDumosois during his match. "I wish that all the chair umpires were likeMohamed Lahyani because I believe he's the best out in the game, and we need morelike him in tennis because he's fair to everyone. I feel like some of them havepreferences when they are on the court." Spanish 10th seed RobertoBautista Agut succumbed in five sets to Mikhail Kukushkin of Kazakhstan whileMarin Cilic, the 2014 champion, advanced in straight sets over Slovakia'sMartin Klizan.

Germany'ssixth-seeded Alexander Zverev battled into the second round by defeatingMoldova's Radu Albot 6-1, 6-3, 3-6, 4-6, 6-2 and leading US hope John Isnersmacked 29 aces in a routine win over Guillermo Garcia-Lopez of Spain.

Wimbledonchampion Simona Halep, ousted in the opening round the past two years atFlushing Meadows, outlasted US lucky loser Nicole Gibbs 6-3, 3-6, 6-2 whiletwo-time runner-up Caroline Wozniacki rebounded from a woeful start to beatWang Yafan in three sets.

Nadal launcheshis bid for a fourth US Open crown in the night session on Ashe againstAustralia's John Millman, the conqueror of Roger Federer in the last 16 here ayear ago. The Spaniard owns 18 Grand Slam titles, two shy of Federer's all-timerecord. Along with defending champion Novak Djokovic the "Big Three"have combined to win the past 11 majors and are again strong favorites. SloaneStephens, the 2017 US Open winner, takes on Russian qualifier Anna Kalinskayain round one, with 15-year-old Wimbledon sensation Coco Gauff making her NewYork debut against Russia's 76th-ranked Anastasia Potapova. Australianfirebrand Nick Kyrgios has been assigned the "graveyard shift" as thelast match on Louis Armstrong against Steve Johnson. - AFP