NEW YORK (Reuters) -Czech Karolina Muchova delivered a flawless display of serve-and-volley tennis to knock twice champion Naomi Osaka out of the U.S. Open with a 6-3 7-6(5) second-round victory on Thursday.
Muchova enjoyed the best season of her career last year before a wrist injury sidelined her for 10 months, but she looked back in her prime at Arthur Ashe Stadium as she set up a third round meeting with unseeded Russian Anastasia Potapova.
Four-times major winner Osaka of Japan, who missed last year's tournament while on a maternity break, was brilliant in her opening round win over 10th seed Jelena Ostapenko but a handful of costly mistakes sunk her chances against Muchova.
"I know she's amazing player and that I have to bring the A-game to have a chance," said Muchova, who returned to the tour in June. "I was just trying to be really focused on myself."
The two big servers were deadlocked early in the match before Muchova converted a break point when she forced Osaka into a backhand error in the seventh game, and the former world number one dropped serve again in the ninth.
Muchova, a semi-finalist last year, looked in cruise control with an easy hold in the opening game of the second set but Osaka battled hard to keep the match tight, fending off three break points in the next game.
Osaka broke Muchova with a powerful forehand into the corner in the ninth game of the second set and had the momentum as she went up 40-0 in the 10th, bringing the crowd to its feet at the same venue where she beat Serena Williams to win her first Grand Slam six years ago.
However, she let the match slip through her fingers as her forehand began to malfunction, the former world number one throwing her racquet in disgust as she sent one long on the second break point.
Muchova has not had much match experience in 2024 after undergoing wrist surgery in February but looked razor sharp in the tiebreak, firing down a pair of unreturnable serves before Osaka sent one long on the second match point.
"I don't even want to compare myself to last year honestly, but yeah, it was kind of bumpy road," said Muchova.
"I had the surgery, and I didn't know if I will play or not. I'm just really grateful honestly that I'm here, that I can play, that I'm pain-free."
Osaka has kept a busy schedule after returning in January from 15 months away on a maternity break, and she said she would take some positives away from New York despite the early exit.
"During the pressure moments I got nervous, and I don't know if I just have to keep playing more matches and get used to that feeling, especially on a really big stage," said Osaka.
"If I get past the disappointment, I feel pretty proud of myself to have gotten that many opportunities while still feeling like I could have played much better."
(Reporting by Amy Tennery in New York; Editing by Peter Rutherford)