Pennetta, at 33 the oldest first-time Grand Slam finalist in the Open era, on Saturday became the first Italian to win the US Open women's crown with an efficient 7-6 (4), 6-2 victory over compatriot and childhood friend Roberta Vinci.
Heading into the US Open, Roger Federer, Rafael Nadal, Novak Djokovic and Andy Murray have won 36 of the past 38 Grand Slam titles, a stretch dating to the 2005 French Open.
Zheng Jie and Peng Shuai, who are among a group of outstanding Chinese women's tennis players nicknamed the "golden flowers", will clash in the first round of the US Open.
The 2014 US Open begins on Monday with American men seeking to end a Grand Slam drought now more than a decade long. The signs, however, are not promising.
Reigning champion Rafael Nadal pulled out of the US Open because of an injury for the second time in three years Monday, leaving Novak Djokovic and Roger Federer as the men to beat at the year's last Grand Slam tournament.
Ageless Swiss adds another 'big' trophy to overflowing cabinet
By now, everyone knows Roger Federer's itinerary for Cincinnati: Get his game in order, raise the winner's trophy, leave town with a lot of confidence for the US Open.
Top-ranked Novak Djokovic was upset by 13th-seeded Jo-Wilfried Tsonga on Thursday in the Rogers Cup, falling 6-2, 6-2 in only 63 minutes in the third round.
Two-time major champion Li Na pulled out of the US Open on Thursday because of a knee injury which she said has bothered her for several months.
Wimbledon champion Andy Murray is unlikely to play again this season after pulling out of next week's Thailand Open to undergo minor back surgery.
Playing the Davis Cup on clay in Madrid this week is not ideal preparation for the hard-court swing in Asia and an assault on the number one ranking, according to newly crowned US Open champion Rafa Nadal.
Britain's Andy Murray joined world number one Novak Djokovic and newly-crowned US Open champion Rafa Nada las definite qualifiers for the ATP World Tour finals on Tuesday but Roger Federer faces a battle to make the eight-man field.