NEW YORK — Flavia Pennetta knew her opponent's game almost as well as she knows her own.
She came out a winner Wednesday over Roberta Vinci in the most important meeting between the Italians over a friendship and rivalry that has lasted more than 20 years.
Blunting Vinci's net attacks, taking away her deft drop shots and preying on her nerves, Pennetta made it to her first Grand Slam semifinal and climbed back to the top of Italy's competitive tennis ladder Wednesday with a 6-4, 6-1 win at the U.S. Open.
"I know how she plays, she knows everything of me," Pennetta said about her 10th-seeded opponent. "We get in the court, and I think today was more about inside, not about tennis. It was about how you play, how you feel in the court, and how can you handle the situation."
Pennetta will play the winner of Wednesday's later quarterfinal between No. 2 Victoria Azarenka and 48th-ranked Daniela Hantuchova. No. 1 Serena Williams and No. 5 Li Na won Tuesday to secure spots in the other semifinal.
After Pennetta's win, eighth-seeded Richard Gasquet got the first spot in this year's men's semifinals, defeating No. 4 David Ferrer 6-3, 6-1, 4-6, 2-6, 6-3 in a match that ran 3 hours, 23 minutes. Gasquet made his second Grand Slam semifinal, the only other coming at Wimbledon in 2007.
Gasquet came in off a five-set win over Milos Raonic in the fourth round that improved him to 6-12 in five-setters for his career. Ferrer was 19-9. After Ferrer won the third and fourth sets to even the match, he looked like a good bet to finish the comeback.
"He's a big fighter," Gasquet said. "I knew I had to serve well. It's important against a big player like that."
Indeed, Gasquet got 70 percent of his first serves in during the fifth set and saved the only break point against him. He'll face the winner of a later quarterfinal between No. 19 Tommy Robredo and No. 2 Rafael Nadal.
"The last time I beat him, I was 13 years old," Gasquet said about Nadal. "I've beaten him one time in my life."
Indeed, Nadal has won all 10 meetings between the men on the pro circuit.
The women's match marked the ninth meeting between Vinci and Pennetta, who, back in 2009, became the first Italian woman to crack the top 10. But she fell out of the spotlight in her country's tennis scene after the emergence of Vinci and Sara Errani, combined with a wrist injury that sidelined her during the end of last season.
Pennetta came into Flushing Meadows ranked 83rd, but will leave with victories over both of Italy's top players.
After her win over Vinci, the Italians met at the net and hugged. Vinci gave Pennetta a kiss on the cheek and told her, "Brava."
"She's someone who, when she wants something, she wants it all costs, which is the right way to be," Vinci said. "It might seem strange to say it, but it's great when a person gets back to this level after an operation. She deserves to be in the semifinals."
Unlike most women in this era of baseline tennis, Vinci attacked the net 34 times. But she won only 18 of those points. She finished with 14 winners and 28 unforced errors. Trailing 5-4 in the first, Vinci saved a pair of set points and had two chances to break, but couldn't convert either. Vinci attacked the net on the last two points of the set, but Pennetta hit shots Vinci couldn't handle both times to close things out.
The second set took only 24 minutes.
Vinci said her style is, well, her style, and it has served her well through a career that brought her into the top 15 for the first time this summer.
"Yes, of course I have a different kind of tennis," she said. "This is my key. Sometimes it helps me, sometimes not. Depends, of course, the opponent."
In this case, the opponent knew what to expect. No big surprise considering they've known each other since they were juniors, have played on Italian Fed Cup teams together and have even played doubles together on the tour. After completing the win that gave her a 5-4 edge in the series against Vinci, Pennetta spoke with reverence about her friend.
"She's Roberta, and she's the only one," Pennetta said.
Vinci acknowledged that, yes, there were nerves, but not necessarily because of the person on the other side of the net. This was Vinci's third straight match against an Italian foe.
"By now, I'm used to playing (them). It's not like this was the first," she said. "There's always pressure. Even if Williams was on the other side, there would have been the same amount of tennis. It didn't have the sort of effect you might think."
This was Pennetta's fourth straight win over a seeded opponent — a stretch that began with a 6-3, 6-1 win over fourth-seeded Errani and also included a victory over No. 27 Svetlana Kuznetsova, the 2004 U.S. Open champion.
"I play good tennis with Sara, with Kuznetsova," Pennetta said. "Every day, much better and better."
Pennetta hasn't lost a set en route to the final four of the year's last major.
Pennetta is 31, while Hantuchova and Vinci are both 30 — part of a group of five thirty-somethings to reach the quarterfinals this year, matching the most in the Open era of Grand Slam tennis.
"It's good to stay physical, in a good way, and play this good tennis at this age, of course," Pennetta said. "I'm proud of (myself) now. I'm 31, and physically, I feel good finally. I'm in the first semifinal in Grand Slam. There is nothing to say more."