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.
Defending champion Serena Williams walloped Spain's Carla Suarez Navarro 6-0 6-0 to race into the semifinals of the US Open on Tuesday.
After crashing out in the fourth round of the US Open against an opponent who had never before beaten him, 17-time Grand Slam winner Roger Federer shrugged off any notion he might quit after Monday's loss.
Lifelong friends Roberta Vinci and Flavia Pennetta, along with Daniela Hantuchova, reached the US Open quarterfinals on Monday to ensure five women over the age of 30 will be in the last eight.
Rafael Nadal believes that facing Roger Federer at the US Open might have to remain an intriguing fantasy after the worrying decline of the Swiss superstar continued in New York.
Li Na broke another barrier for Chinese tennis, becoming China's first semifinalist at the US Open by beating Russian Ekaterina Makarova 6-4 6-7(5) 6-2 on Tuesday at windy Flushing Meadows.
Rafael Nadal came back to beat 22nd-seeded Philipp Kohlschreiber of Germany 6-7 (4), 6-4, 6-3, 6-1 on Monday night in the fourth round.
Former world number one Roger Federer was knocked out of the US Open on Monday by Spain's Tommy Robredo.
New high in lows for US tennis as host nation shut out of last 16
In an all-American showdown, defending champion Serena Williams overpowered Sloane Stephens 6-4, 6-1 on Sunday to reach the US Open quarterfinals and exact revenge for her shocking loss to her younger compatriot at the Australian Open.
China's power hitter routs Jankovic, but she'd rather shine in daytime
Agnieszka Radwanska refused to use a recent personal tragedy as an excuse for her shocking exit from the US Open on Sunday.
Agnieszka Radwanska refused to use a recent personal tragedy as an excuse for her shock exit from the US Open on Sunday.