Paris - Spain's Fernando Verdasco and Russia's Nikolay Davydenko tightened their grips on the remaining ATP World Tour Finals places by reaching the third round of the Paris Masters on Tuesday.

Sixth seed Davydenko cruised past Germany's Benjamin Becker 6-2, 6-1 at the Bercy arena but seventh seed Verdasco was made to dig deep against Italian Andreas Seppi before eventually prevailing 6-7 (3/7) 6-4 6-4.

With six of the world's top players already qualified for the year-ending event in London, Davydenko and Verdasco are the hot favourites to secure the last two places.

Verdasco relinquished a 3-0 lead against Seppi before conceding the first set on a tie-break and he allowed the Italian to come back from 2-0 down in the second set before breaking for a 5-4 lead and levelling the match.

The Spanish world number eight broke early again in the decider before once again letting his opponent back into the set, but he finally secured the decisive break in game nine when Seppi batted a backhand beyond the baseline.

Verdasco's victory means that Czech Radek Stepanek and Croatia's Marin Cilic can no longer qualify for the season finale, but Cilic will have the chance to exact swift revenge on Verdasco if he comes through his second-round match against Polish qualifier Lukasz Kubot.

Davydenko, meanwhile, will next face either Croatia's Ivo Karlovic or ninth seed Robin Soderling of Sweden, who is one of the Russian's rivals for a World Tour Finals place.

"There are guys here who need to win this tournament (to qualify for the World Tour Finals), just getting to the final is not enough," said Davydenko.

"It's a good feeling. With everyone here, (Roger) Federer and (Novak) Djokovic, it's a very tough draw and it's not so easy for (Jo-Wilfried) Tsonga or Soderling or Verdasco to reach the final and win the tournament."

French defending champion Tsonga and Chile's Fernando Gonzalez are the two other players seeking to overhaul Davydenko and Verdasco, with Tsonga set to begin his title defence against Spain's Albert Montanes.

Earlier, unheralded French qualifier David Guez, the world number 179, stunned Swiss world number 21 Stanislas Wawrinka 6-3 6-4 to set up a second-round meeting with countryman Gael Monfils.

Julien Benneteau beat Germany's Philipp Petzschner 4-6 7-5 6-3 in his first-round match to book a date with top seed Federer but fellow Frenchman Jeremy Chardy went down 7-6 (8/6) 7-5 to Argentina's Juan Monaco.

Spain's Nicolas Almagro beat Marco Chiudinelli of Switzerland 6-2 6-4 and will face second-seeded compatriot Rafael Nadal in round two.

Nadal and Federer form part of a star-studded draw in the €2.75m final Masters tournament of the year, with injured American Andy Roddick the only absentee from the world top 15.