Juan Carlos Ferrero became the first seeded casualty at the US Open after he was beaten 6-3, 6-4, 6-4 by fellow-Spaniard Feliciano Lopez in the first round on Monday.
The 21st seed, runner-up here in 2003, was outplayed throughout by Lopez, who will now play Russian Igor Andreev.
"I served so badly today," Ferrero said.
"The balls here don't help me because I like to hit with a lot of spin but when you hit the ball it's like they are dead. If you can serve big and hit the ball flat, it's better."
The only time Ferrero looked like making a fight of it was when he recovered an early break in the third set but world number 60 Lopez broke again to seal victory.
"It's just another tournament," a despondent Ferrero said.
"I know it's a Grand Slam, but I lost in the second round here last year. The world is still turning."
Ai Sugiyama needed just 67 minutes to advance to the second round with a 6-3, 6-1 rout of Slovenian qualifier Andreja Klepac.
Sugiyama, seeded 28th, broke Klepac in the opening game of the match and never looked back.
"The first two games were the key," Japan's Sugiyama said. "She was serving in the first game and led 40-15 but I broke her right away.
"In the next game, I'm serving and she had two break points at 15-40 but I held my serve. "So I go up 2-0 and I started to get into a rhythm. It was very huge."
The 32-year-old, ranked 30th in the world, was never broken and held a 63-39 advantage in overall points won.
"I'm pleased with the way I played today," she said. "I always get tight at the first match (of the tournament). But today was no problem."
In the second round, Sugiyama will face Russian Ekaterina Makarova, who defeated Julie Schruff of Germany 6-1, 0-6, 6-2.
Sugiyama is playing in her 14th consecutive U.S. Open but has never advanced past the fourth round.
Results:
Men's singles: Donald Young (US) beat Chris Guccione (Australia) 6-7(2), 6-3, 6-2, 6-3; Igor Andreev (Russia) beat Robert Kendrick (US) 7-6(4), 6-3, 6-4; Feliciano Lopez (Spain) beat 21-Juan Carlos Ferrero (Spain) 6-3, 6-4, 6-4; 4-Nikolay Davydenko (Russia) beat Jesse Levine (US) 6-4, 6-0, 6-1.
Women's singles: 3-Jelena Jankovic (Serbia) beat Jarmila Gajdosova (Slovakia) 6-2, 7-6(2); Olga Govortsova (Belarus) beat Sofia Arvidsson (Sweden) 6-3; 2-6, 6-3; Ekaterina Makarova (Russia) beat Julia Schruff (Germany) 6-1, 0-6, 6-2; Elena Likhovtseva (Russia) beat Lauren Albanese (US) 6-0, 6-2; 15-Dinara Safina (Russia) beat Catalina Castano (Colombia) 6-2, 6-3; 28-Ai Sugiyama (Japan) beat Andreja Klepac (Slovenia) 6-3, 6-1.
