NEW YORK Second seed Agnieszka Radwanska wore down former world number one Jelena Jankovic of Serbia 6-3 7-5 on Saturday to book her place in the fourth round of the U.S. Open.
In steamy temperatures, the Wimbledon runner-up was too consistent and too battle-hardened for the world number 27 as she won through in one hour, 38 minutes.
Jankovic has slipped down the rankings since she hit world number one in 2008 but at her best, she is a match for Radwanska, as the Pole admitted.
"She's a very consistent player," Radwanska said. "We played against each other a couple of times and they were always long and tough matches. I was prepared for that.
"Especially with the hot conditions, you really have to fight more yourself than against the opponent, because today was really hot."
Radwanska admitted that sometimes it was as if she was playing against a mirror, so alike are their styles.
"We play a little bit similarly," Radwanska said. "That's why I think we always playing long rallies, long games, long points."
Radwanska said she expects to see Jankovic back up nearer the top of the rankings sooner rather than later.
"She was number one and she was in the top four for a long time. In tennis, you can't really play amazing all the time," she said.
"Now she's coming back (to her best). She really was playing good today. If she's going to play like that, she will be back (toward the top) soon."
Radwanska now plays Italy's Roberta Vinci, who upset 13th seed Dominika Cibulkova of Slovakia to reach round four.
"She's another tough opponent, no mistakes at all," she said. "A lot of slices, spin, and then suddenly some strong hits. Against her I just have to do everything (well).
"The last time we played, I think it was Madrid. It was clay, but that clay was faster than the hard courts here."
(Editing by Steve Ginsburg)