U.S. Open champion Kim Clijsters is already relishing the prospect of renewing her long rivalry with her fellow Belgian Justine Henin.

The pair, both on the comeback trail, could meet as early as this weekend if they reach the final of the Brisbane International and both have kept up their end of the bargain so far.

Henin, playing her first match in 20 months, beat Russia's Nadia Petrova on Monday night and Clijsters followed up by whipping Australia's Alicia Molik 6-0 6-3 on Tuesday.

Clijsters needed just 60 minutes to dispose of Molik, who has been her friend since they were teenagers starting out on the junior circuit, but admitted she was already thinking about Henin.

"Those are the matches that you want to do it for," Clijsters said. "This is why we love to play tennis, for those big matches.

Clijsters said that although she was not at the courts on Monday night when Henin was playing, curiosity got the better of her and she watched the match on television.

"On TV it is hard to tell, once you stand in front of her I think you get a better feel," Clijsters said.

"But she was very impressive, I thought. She didn't look like she had left."

Former Australian Open finalist Marcos Baghdatis of Cyprus was made to work much harder than Clijsters in his 7-5 7-5 first round win over American Mardy Fish.

"It wasn't my best match but I am happy," Baghdatis said. "In the off season I worked hard on my fitness. I am quicker, fitter and I am enjoying it."

Baghdatis will meet Czech Thomas Berdych in the second round after the fourth seed defeated Australia's Nick Lindahl 6-2 6-4.

American James Blake beat his countryman Sam Querrey 4-6 6-3 6-4 while Australian wildcard Carsten Ball defeated German Mischa Zverev 7-5 6-1 to set up a meeting with top seed Andy Roddick.