Wednesday, the top three women's seeds advanced to the semifinals.
No. 1 Amelie Mauresmo needed just 62 minutes to beat 12th seed Dinara Safina 6-2, 6-3. Mauresmo had lost in the U.S. quarterfinals in four of the previous five years before getting within two match victories of her third Grand Slam title of the year.
Jankovic upset fourth seed Elena Dementieva 6-2, 6-1 on Tuesday.
Ninth seed Andy Roddick had reached the men's semifinals, and he won't have to face No. 2 Rafael Nadal. Roddick advanced with a 6-3, 7-5, 6-4 triumph over No. 15 Lleyton Hewitt, putting the American in the semis against Mikhail Youzhny.
Youzhny pulled off the upset by downing Rafael Nadal 6-3, 5-7, 7-6, 6-1. Before the Open, the 54th-ranked Youzhny had never gone past the fourth round in a Grand Slam event.
Top seed Roger Federer moved into the quarters by beating unheralded Marc Gicquel. And fifth-seeded James Blake stopped number-12 Tomas Berdych 6-4, 6-3, 6-1 in a fourth rounder.
Seventh-seeded Nikolay Davydenko returned to the court and won six straight games to finish off a 6-1, 5-7, 6-3, 6-love victory over Andy Murray.
And 14th-seeded Tommy Haas outlasted former champion Marat Safin 4-6, 6-3, 2-6, 6-2, 7-6.