NEW YORK — A year ago, Flavia Pennetta was hanging out at her parents’ home on Italy’s heel, recovering from right wrist surgery, watching the US Open on TV — and wondering how long it would take her to get back on the tennis tour.
Look at her now.
Pennetta is a Grand Slam semifinalist for the first time at age 31, and in her 41st major tournament. Unseeded, ranked only 83d, Pennetta got to the final four at Flushing Meadows with a 6-4, 6-1 victory Wednesday over another Italian, 10th-seeded Roberta Vinci, who happens to be her long-time friend and former doubles partner.
In the other women’s quarterfinal match, second-seeded Victoria Azarenka moved a win away from a possible showdown with Serena Williams, topping Daniela Hantuchova, 6-2, 6-3.
Azarenka has beaten top-seeded Williams twice this year, including last month in the final of a tuneup tournament in Cincinnati. Last year, Williams topped Azarenka in three sets for her fourth Open title.
The quarterfinal against 48th-ranked Hantuchova wasn’t much of a roadblock. Hantuchova, returning to the US Open quarterfinals for the first time since 2002, broke Azarenka’s first service game in both sets but gave back both breaks right away.
Standing in the way of a Williams-Azarenka final are fifth-seeded Li Na, who plays Williams in Friday’s semifinals, and Pennetta, who goes against Azarenka.
Pennetta and Vinci know each other’s games, and each other’s personalities, perfectly. While Pennetta was laid up after her operation last September, they spoke on the phone and sent text messages.
‘‘She went through some ugly times,’’ said Vinci, who lost in last year’s US Open quarterfinals to yet another Italian, her current doubles partner Sara Errani.
‘‘But Flavia is strong-headed. She’s stubborn,’’ Vinci continued. ‘‘She’s someone who, when she wants something, she wants it at all costs, which is the right way to be.’’
Back in 2009, Pennetta was the first woman from Italy to be ranked in the top 10.
But she was off the tour from August 2012 until February 2013, and dropped down as far as 166th after her comeback began with a 3-7 record.
Her ranking was still too low last month to get directly into the US Open’s main draw, but another player’s withdrawal put Pennetta in the field.
Taking full advantage, Pennetta has won five consecutive matches in straight sets, eliminating four seeded players along the way.
Pennetta, 31, and Vinci, 30, were two of five thirtysomething women among the eight quarterfinalists in New York, tying a Grand Slam record for the Open era, which began in 1968. Two of the others play each other in Friday’s semifinals: No. 1 Serena Williams and No. 5 Li Na are both 31.
Pennetta and Vinci have known each other, and played against each other, since they were about 10.
Pennetta explained she handled the circumstances better than Vinci, if only barely.
‘‘In the beginning, we didn’t play good tennis. I was tight. She was tight,’’ Pennetta said. ‘‘When I won the first set, I just [relaxed] a little bit and tried to play better. But the day was tough for both of us.’’
Truth is, Vinci did not play well, accumulating twice as many unforced errors, 28, as winners, 14.
She stuck to her usual strategy, which involves plenty of rushing the net, but she won only 18 of 34 points when she moved forward.
Vinci is 0-2 in Grand Slam quarterfinals, and both of the losses came at the US Open against Italians she’s close to: She and Errani are the defending women’s doubles champions in New York, and will face the Williams sisters in this year’s quarterfinals.
The Williams sisters overcame two service breaks in the second set to advance to the quarterfinals with a 6-1, 7-6 (3) victory over Anastasia Pavlyuchenkova and Lucie Safarova.
Errani and Vinci beat the sisters in three sets in the Australian Open quarterfinals.
‘‘We learned from the match in Australia,’’ Venus Williams said. ‘‘Obviously, they play well, they play often. They’re a great team, so we’re going to learn from that and go for it tomorrow.’’