Second-seeded Belarusian Victoria Azarenka has booked her place in the quarter-finals of the U.S. Open on Tuesday when she beat Serbia's Ana Ivanovic 4-6, 6-3, 6-4.

The Belarusian tennis star overcame 13th-seeded Ana Ivanovic an open-set down at the Ashe Stadium in a match that was postponed because of rain on Monday at the USTA Billie Jean King National Tennis Center.

The Belarusian's next opponent is unseeded Slovakian Daniela Hantuchova, who beat American wildcard Alison Riske on Monday to reach her first quarter-final.

Azarenka is the two-time reigning Australian Open champion and lost to Serena Williams in last year's memorable U.S. Open final.

The 2012 runner-up at Flushing Meadows needed 2 hours, 10 minutes to beat Ivanovic, the 2008 French Open champion.

"I was, like, sleeping," Azarenka said in an on-court interview. "I really had to wake up in the second set and try to fight for points."