WIMBLEDON, England(AP) Justine Henin and Kim Clijsters will face off again, this time in the fourth round at Wimbledon.

Monday will mark the latest installment in a rivalry between the Belgian rivals, who both own Grand Slam titles, rose to the top, retired, and came back around the same time. Neither has won Wimbledon, and their head-to-head record stands at 12 wins each.

For all the symmetry, there are plenty of differences. Henin is slender, a champion with a sublime one-handed backhand and a natural slice who makes up for a lack of physical strength with touch and deft volleys. Clijsters is bigger and stronger, a scrappy defender who bludgeons balls from the backcourt.

I would say, in our first career, we never played our best tennis against each other,'' Henin said.This year, it's been two times 7-6 in the third. So very close, and I hope it's going to be another good one.''

Both players beat Russian players on Friday, and their first sets each lasted 27 minutes. Henin, the No. 17 seed, won 6-1, 6-4 against 12th-seeded Nadia Petrova on Centre Court after recovering from a 1-3 deficit in the second set. No. 8 Clijsters defeated No. 27 Maria Kirilenko 6-3, 6-3 on Court 2.

Clijsters became a mother during her tennis absence and won her second Grand Slam title, again at the U.S. Open, soon after her return last year. Earlier this year, Clijsters beat Henin in the final of Brisbane and the semifinals of Miami, both in third set tiebreaks.

Clijsters said she and Henin, who has won seven major titles, brought out the best in each other in those ``up and down'' matches, with Clijsters starting off well and Henin countering in the second set.

Growing up together, she's always been the more touchy player,'' Clijsters said.She has good hands. Obviously, the slice is something she was naturally born with. You know, that's something that for me that took a lot more hard work ... I'm bigger, stronger in a sense, but I think she's improved a lot in that aspect, as well. I think she's definitely improved a lot on her serve.''

Two of the matches between them came at International Tennis Federation events at the start of their careers. The rest were at the tour level. Henin leads on grass, 3-1, with the only loss coming when she retired from a match. In their only Wimbledon matchup, Henin won in the semifinals in 2006. She has lost twice in the final at Wimbledon and needs a title at the All England Club to complete a career Grand Slam.

Clijsters has never reached the championship match at Wimbledon.

At 28, Henin is a year older. Their birthdays fall in the same month - June 1 for Henin, June 8 for Clijsters. They have each won two titles this year, though Henin holds the edge in career titles at 43, six more than her rival.

Henin returned to the tour in January, 1 1/2 years after abruptly quitting when she was ranked No. 1 in the world and poised to defend her title at the French Open. Away from the court, Henin did charity work, starred in television reality shows in Belgium, and in her view, became more open and fulfilled outside the ``bubble'' of tour pressure and competition.

She has said she was inspired to return to tennis by Roger Federer's French Open win last year, as well as Clijster's triumph at the U.S. Open just a month after coming out of retirement. The pair played singles for Belgium in a Fed Cup win over Estonia in April.

We grew up at the same time. We arrived at the top at the same time. We almost retired at the same time. We almost came back at the same time. So we are very close,'' Henin said.We can feel we grew up a lot, both of us. I mean, Kim, of course, having a baby, and the distance I took also for two years.''

She said she would have to move forward on the court and be aggressive to counter Clijsters' power and ``big weapons,'' as well as her combative spirit.

It could go either way,'' Clijsters said.I think that just shows in the results we've had against each other, all the matches.''