NEW YORK (AP) — Nikolay Davydenko looked untouchable for the fifth straight match, beating 10th-seeded Tommy Haas 6-3, 6-3, 6-4 yesterday to reach the semi-finals of the US Open.

Davydenko is the only man who has not lost a set in the tournament.

The victory for the fourth-seeded Russian comes while he has been asked repeatedly for a month about an ATP gambling probe and expects to meet soon with investigators. A British online gambling company tracked bettors putting 10 times the usual amount of money on a match he played in August, most of it backing his 87th-ranked opponent; Davydenko quit in the deciding set with a foot injury.

"I don't care what's happening out there. For me, it's more important what I do right now here," he said.

Davydenko again denied any involvement with gamblers. He also offered a possible reason why so much was bet against him in that match in Poland: inside information that he'd been hurting for a few days.

Somebody may've known Davydenko was hobbled "and then guys now are putting this money," he said.

Next up, Davydenko was to play the winner of last night's match-up between No. 1 Roger Federer and No. 5 Andy Roddick. Davydenko has never beaten either one — he's 0-9 against Federer and 0-4 versus Roddick.

Also at night, two-time Open champ Venus Williams was to play No. 3-seeded Jelena Jankovic in the quarter-finals.

Davydenko beat Haas in the quarters at Flushing Meadows for the second straight year. This was a frustrating defeat for the German, who flung his racket into the net, hit a ball into the stands and chastised the chair umpire.

"I don't know how he does it. You wonder sometimes," Haas said. "I don't have a hat, but I tip it to Nikolay." Davydenko joined a pair of Russian women in the semi-finals.

Svetlana Kuznetsova advanced that far for the first time since winning the 2004 title, beating unseeded Agnes Szavay 6-1, 6-4.

"It's my favourite tournament. I love New York," said the No. 4-seeded Kuznetsova, who's been wearing Yankees baseball caps when she's not playing. "It doesn't matter how I feel, I just come to this court and always want to give my best."

She'll face fellow countrywoman Anna Chakvetadze, who swept the last six games to eliminate No. 18 Shahar Peer 6-4, 6-1.

It will be the sixth-seeded Chakvetadze's first Grand Slam semi-final. Kuznetsova can count on an edge in experience, having made it to the 2006 French Open final, in addition to claiming her only major championship at Flushing Meadows three years ago.

Since that breakthrough, though, Kuznetsova has had her problems at the American major. In 2005, she became the first defending women's champion to lose in the US Open's first round. In 2006, she exited in the fourth round.

This year, she's brimming with confidence. "Definitely. Yes," Kuznetsova said. "Of course I believe in myself."

She ended an impressive US Open debut by the 18-year-old Szavay. Kuznetsova gained some insight into Szavay's game when they met in the final of a hard-court tournament at New Haven, Conn., on the last weekend of August. Szavay quit during that match because of a back injury, but recovered well to make her first major quarter-final in only her third Slam, and she hadn't lost a set until yesterday.

The 20-year-old Chakvetadze never had been as far as a major quarter-final until this year, when she lost at that stage at the Australian Open and French Open.