World No.81 Alison upsets Kvitova in US Open

[1]

Serena Williams and Sloane Stephens are through to a highly anticipated matchup in the round of 16 at the US Open, where they're joined by a less expected American, Alison Riske.
Lleyton Hewitt downs Juan Martin Del Potro as US Open magic returns
Maybe Riske's run isn't that much of a surprise considering her recent surge. The 23-year-old came into the summer having never accomplished any of these feats: winning a match in a Grand Slam tournament, at a WTA Tour event on hard courts, or against at top-10 foe.
She's now achieved all that, her latest breakthrough victory a rout of 2011 Wimbledon champ Petra Kvitova on Saturday. Riske won 6-3, 6-0, taking the last eight games against the seventh-seeded Czech.
“I've got a new confidence in myself,“ Riske said through tears in an oncourt interview. “I believe that I belong here.“ She was 0-5 at major tournaments before Wimbledon this year but is 5-1 since.Riske just broke into the top 100 in late July; now she'll likely earn a top-60 ranking.
She has always thrived on grass, making the third round at Wimbledon this year. Now she's starting to figure out the hard courts. Kvitova, who called for a trainer before the final game, had seven doublefaults and 27 unforced errors.
Williams advanced after midnight Saturday morning, beating 78th-ranked Yaroslava Shvedova of Kazakhstan 6-3, 6-1. Much, much earlier, Stephens reached the round of 16 in New York for the first time by beating 23rdseeded Jamie Hampton 6-1, 6-3 in another all-American matchup.
Ever since Stephens announced her presence as a major force with a quarterfinal victory over a hobbling Williams at the Australian Open, tennis fans have craved a rematch on the biggest stage. Now it's here.