Second seed Jelena Jankovic and fifth seed Elena Dementieva booked their spots in the quarter-finals of the US Open with victories on Sunday.
Jankovic dropped her opening set against Caroline Wozniacki but advanced with a 3-6 6-2 6-1 victory over the Dane.
After suffering through a slow start, the 23-year-old Serbian kicked things into gear, wrapping up the final two sets in just over an hour.
"In the first set, she played quite solid," Jankovic said.
"She put all these balls back. She didn't make any errors. I was the one who was all over the place and I couldn't really find my rhythm in these kind of conditions."
"I had to change something to get myself together again and do the right things. I did that. I just cruised through the second and third set, and happy to get through in this way."
Jankovic appeared a bit sluggish early on but was still able to secure a place in the quarter-finals of the year's final Grand Slam for the third straight time.
It was Jankovic's second three-set win in two career meetings with the 18-year-old Wozniacki, whom she beat in the second round at Wimbledon earlier this year.
The next opponent for Jankovic will be Austria's Sybille Bammer, who overcame a slip-up in the second set en route to a 7-6 (7-3) 0-6 6-4 triumph over 12th seed Marion Bartoli of France.
Jankovic, who has never reached a Grand Slam final, has a 6-1 career record against Bammer, winning the last five meetings.
Newly-crowned Olympic champion Dementieva also reached the round of eight, posting a convincing 6-4 6-1 triumph over China's Li Na in a late match.
The Russian extended her hardcourt win streak to 10 matches and avenged a loss to the Chinese star in Sydney in 2007.
Dementieva, a runner-up at Flushing Meadows in 2004, next faces 15th seed Patty Schnyder of Switzerland, who recorded a 4-6 6-3 6-3 victory over No.28 Katarina Srebotnik.