Andy Roddick [Images] and Juan Martin Del Potro were firmly on track for a Masters Cup berth as they strolled into the third round of the Paris Masters on Tuesday.

American Roddick, sixth in the ATP Race, beat Spaniard Feliciano Lopez 6-3, 6-4 while Argentine Del Potro, who is seventh, thrashed Croatian Mario Ancic 6-0, 6-4.

Three spots for next month's season-ending tournament in Shanghai are still up for grabs in Paris with Roddick, Del Potro and France's [Images] Gilles Simon, eighth in the ATP Race, occupying the remaining places at the start of the tournament.

Big-serving Roddick needed just one break in each set to beat Lopez, who made too many unforced errors to bother the 2003 US Open [Images] champion.

"I felt like I hit the ball pretty well tonight. You know, I wanted to try to hit it firm and deep, because anything short and he tries to get in and then starts putting pressure on. It felt pretty good tonight," said Roddick.

World number three Novak Djokovic [Images], who has already secured his Masters Cup place in China, reached the third round after Russian Dmitry Tursunov [Images] retired with a shoulder injury.

The third-seeded Serb, who was 6-2, 4-3 ahead, will next meet Czech Radek Stepanek or France's Jo-Wilfried Tsonga, whom he beat in the Australian Open [Images] final in January.

Djokovic got off to a flying start, breaking in the second and eighth games to quickly bag the first set, with Tursunov calling the trainer in to treat his shoulder.

Following an early exchange of breaks, the Serb broke his opponent's serve again and one game later Tursunov retired.

DJOKOVIC FIGHTING

"I am still trying to find my top form. Lately, I have been struggling on the court. But still, I am fighting," Djokovic told reporters. "I know that I have to fight for every point and just find my best shape."

Del Potro overwhelmed Ancic and faces a tricky third-round encounter with German Nicolas Kiefer or fellow Argentine David Nalbandian, who beat him in the semi-finals of the Swiss Indoors last weekend and still hopes to qualify for the Masters Cup.

"I improved my game a lot and had a very good summer in the US," said Del Potro, who won the Los Angeles and Washington titles in August.

"I don't change my tactics but I'm playing more aggressive and I'm serving very well now. The key to being a very good player is to play the important points better and that's what I'm doing now."

Local favourite Gael Monfils was the first player to reach the third round with a 6-4, 6-4 win over Argentine qualifier Juan Monaco.

The Frenchman, seeded 16th, will next meet world number one Rafael Nadal [Images] if the Spaniard wins his second-round match against France's Florent Serra, who beat Argentine Guillermo Canas 4-6, 7-5, 6-3.

In first-round action, Swede Robin Soderling, who won the Lyon Grand Prix on Sunday, made light work of French wild card Josselin Ouanna with a 6-3, 6-4 win.

The world number 18 will on Wednesday meet second seed Roger Federer [Images] of Switzerland [Images], who is looking to avoid a first year without a Masters Series title since 2003.

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