The sledgehammer groundstrokes of Juan Martin del Potro will provide the ultimate test of Novak Djokovic's armor-plated confidence in the most eagerly anticipated match of the French Open so far later today.

They are only colliding in the third round because of Del Potro's injury problems which sent him tumbling down the rankings and their clash would not look out of place as a grand slam final.

Djokovic has been supreme so far, taking his winning streak this year to 39 with two comfortable rounds but the 25th-seeded Del Potro, who has been plagued with wrist and then hip problems, is capable of beating anyone on his day.

"It's going to be a great match, a battle, and he has always had a quality to be at the top of the men's game," Serbian Djokovic said of the 2009 US Open champion.

"He is playing equally well on any surface. Big serve, great groundstrokes. For his height he's moving really well. He's just overall a top player for me.

"He's unfortunately had to take some time off because of the injury, but he's coming back now.

"It's going to be a big challenge for both of us, obviously a great match for people to see."

World number four Andy Murray will definitely be tuning in.

"Because the court is playing fast, I think that that's good for Juan," the Briton told reporters. "And I'll definitely watch a little bit of that match.

"It's a great, great third round."

Before Djokovic and Del Potro lock horns, last year's women's runner-up Samantha Stosur of Australia opens proceedings on Court Philippe Chatrier against Argentina's Gisela Dulko as the eighth seed continues her search for a maiden slam title.

Third seed Roger Federer, who has cantered through his first two matches, will be up against Serbian 29th seed Janko Tipsarevic on court Suzanne Lenglen.

Women's defending champion Francesca Schiavone, who has revelled in her return to the scene of her most memorable moment, will be on the same court against China's Shuai Peng.