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.
Andy Murray watched a 130 mph ace zoom by to create a two-set deficit at the US Open, and then sat in his changeover chair and cursed at himself, over and over and over.
Roger Federer produced another bright effort while Britain's Johanna Konta continued to enjoy her time in the sun and the US Open spotlight on Saturday reaching the fourth round of a grand slam for the first time.
Second-seeded Simona Halep made quick work of her third-round match at the US Open.
Second seeded Simona Halep worked the night shift for the first time at the US Open and found it to her liking as she steamed past American qualifier Shelby Rogers 6-2 6-3 to reach the fourth round at Flushing Meadows.
Even if her latest troublesome first set had finished only an hour earlier, it seemed a distant memory by the time Serena Williams smacked a cross-court forehand passing winner on the run and wound up doing the splits behind the baseline.
A year after his run all the way to his first Grand Slam final, Kei Nishikori's stay at the US Open lasted only a few hours.
Five-time Grand Slam champion Maria Sharapova withdrew from the US Open on Sunday due to a leg injury.
One year after doping ban, Croatian clinches US Open for first Slam title
While Japanese fans were understandably disappointed after Kei Nishikori missed out on a US Open title, his unprecedented run to the final will do much to boost his career and the sport's popularity in a country where baseball and soccer dominate headlines.
Unable to play in the US Open a year ago because of a doping suspension, Marin Cilic is now the tournament's champion.
Super Serena draws level with Evert and Navratilova on all-time list
A couple of months before Serena Williams capped her dominant run to a third consecutive US Open championship and 18th major singles title Sunday night.