Kim Clijsters gambled and won in her all-Belgian battle with Justine Henin but admitted she was “overwhelmed” in the first set of their Wimbledon encounter.
Clijsters faces a quarter-final meeting with Russian Vera Zvonareva after recovering from a poor start to beat her Fed Cup team-mate 2-6 6-2 6-3.
The victory puts Clijsters 13-12 ahead in past meetings with Henin.
Both had made their Wimbledon comebacks this year after coming out of retirement, and eighth seed Clijsters, who has now won all three of their clashes since Henin rejoined her on the WTA Tour this year, struggled to return serve in the first set.
Henin dominated the rallies despite suffering an elbow injury after a dramatic slip in the third game. She received treatment during and after the set and the match turned suddenly after both players held their first service games in the second.
Clijsters won three games with the loss of just one point as her serve improved and she discovered a way of matching and then edging her compatriot during rallies.
She retained her edge in a tighter third set and broke in the eight game before serving for the match.
Clijsters, who won the US Open last September in only her third tournament since becoming a mother, admitted she had taken risks.
“I was just very overwhelmed in the beginning by the speed of her game,” the 27-year-old said.
“She was definitely overpowering me on every aspect of the match.
“She was serving extremely well, returning extremely well.
“She was just on top of every shot that I hit. I wasn't helping myself by giving her a lot of second serves.
“Because she was playing so well, I started trying to go for the lines, maybe overdoing it a little bit too much. But I had to do that.
“In the second set, I was able to do what I was trying to do at the end of the first set.
“I was definitely going for the lines a lot better, keeping the pressure on her. And I made a lot more first serves.
“I played really good tennis in that second and third set.”