Kim Clijsters admitted she had to dig deep to beat fellow Belgian star Justine Henin and move into the quarter-finals at Wimbledon (Clijsters 4/1 to win Wimbledon).

The two players were back at Wimbledon for the first time since coming out of retirement and it was the 2001 and 2006 finalist, Henin, who got off to the better start.

She took the first set but Clijsters, who won the US Open on her return to professional tennis last year, hit back with the second.

And Henin had no answer to her compatriot in the decider, who ran out a 2-6 6-2 6-3 winner at SW19.

The duo had met twice already this season with Clijsters triumphant on both occasions in a third-set tie-break and so it always looked like Monday?s match would be tight and go the distance.

Clijsters admitted that she was taken by surprise by her opponent’s early form but was able to adjust her game enough to move into the last eight once again.

“She came out of the blocks really fast, really dominating. I felt a little bit overwhelmed,” she told BBC Sport afterwards.

“It was up to me to stay in the points and serve better. That’s how I made the turnaround, a few longer rallies.”

Clijsters will meet Vera Zvonareva in Tuesday’s quarter-finals and will be confident of moving into the last four with her performance against the former world number one.

She reached the Wimbledon semi-finals in 2003 and 2006 and has shown that she can still compete with the best at Flushing Meadows last year despite taking time out of the sport to have a baby.