Paris - Juan Del Potro and Gael Monfils both gained ground in the race for a place at the season-ending championships in China with resounding victories on Tuesday into the third round of the Paris Masters.

Ninth seed Del Potro, playing in pain with a split toenail which will need to be removed at the end of a long season in a month, won the first six games to crush Croatian Mario Ancic 6-0, 6-4.

The 16th seeded Monfils overcame a slow start before overhauling Argentine Juan Monaco 6-4, 6-4.

He and Del Potro are in the hunt for one of three remaining spots for the eight-man Masters Cup in Shanghai from November 9, with all remaining places to be decided this week at the final event on the regular ATP calendar.

With his victory - the 30th of the season - Monfils improved to provisional 13th in the race, with his next match set for Thursday and likely featuring top seed Rafael Nadal.

But Del Potro stands on even more solid ground as he improved to joint sixth along with Andy Roddick, with the American set to open his week later.

"I'm trying not to think of Shanghai - but it's impossible," said the 20-year-old Argentine who also has a Davis Cup final against Spain to look forward to in late November.

"I always wake up thinking of Shanghai or the Davis Cup. It's good in a way as it give me motivation to work and play well."

Del Potro, who exploded into form this summer with four consecutive titles, has won 34 of his last 39 ATP matches.

Monfils fired a dozen aces and broke four times as he played his first match since losing a Madrid quarter-final to Andy Murray.

Swede Robin Soderling put out the potential next wave of French talent as he beat Josselin Ouanna 6-3, 6-3. Philipp Kohlschreiber kept German hopes alive with a defeat of Russian Mikhail Youzhny, 6- 1, 6-4.

Croatian veteran Ivan Ljubicic, the losing 2005 finalist to Tomas Berdych, got off to a good start as he beat Serbian rival Viktor Troicki 6-3, 6-4. dpa