NEW YORK -- What we learned on the seventh day into night ...
1. File this one under "M" for Meltdown. Sunday night started smoothly for Vera Zvonareva. The seventh-ranked Russian took the first set 6-3 against Italy's Flavia Pennetta, reached match point six times in the second set and appeared poised to advance. Then, she unraveled. The long, physical rallies wore on her knees -- both of which were mummified with tape before the match -- but it was her failure to close out the match that opened Pandora's Box. In between sets, Pennetta remained on the court for a trainer to knead her lower back as Zvonareva retreated to the tunnel beneath the stands to cry hysterically. Two lost points into the third set she began to unwrap the support on her left leg, saying it was too tight. The chair umpire refused her request to use scissors to cut the tape before a change of sides. She slipped on a swing, and slapped her right knee three times, ripping off more tape. As Pennetta stroked winners, Zvonareva's head -- more than her knees -- proved to be on the mend. The final set ended 6-0. "She was just angry because of the tiebreak," Pennetta said, noting she had seen similar hysterics before. "With six match points, it's quite normal."
2. Flavia is the flavor of the summer. The 27-year-old became the first Italian ever to be ranked in the top 10 last month, and she doesn't appear ready to stop her ascent. Since Wimbledon, she is 26-4, moving well and mixing various looks. She forced Zvonareva to run down winners in the 3-6, 7-6 (6), 6-0 win. Her serve was not steady but her strategy and stamina won out. She will need to summon both if she wants to get past Serena Williams in the quarters.
3. Taylor Dent left an impression. The serve-and-volley star exited quietly with his straight-sets loss to Andy Murray, but the echoes of his five-set, four-hour win Friday night can still be heard in the Grandstand. Dent fell out of the world rankings after a serious back injury and complex spinal surgery in 2007, but impressed many with his return and ability to still blast a 146 mph serve that electrified the crowd against Murray.
4. Last year's dark horse is the year's Black Beauty.Juan Martin del Potro was nimble around the net, powerful from the baseline and spotted 20 aces in his 6-1, 3-6, 6-3, 6-3 win over Daniel Koellerer. Dressed in a black shirt and shorts, his look is meant to make the statement that he is all business. On serve, the 20-year-old Argentine consistently dialed up aces higher than 130 mph -- including one 134 mph service winner that busted the strings on Koellerer's racket. Star this pony for a backstretch run in your prospectus.