Defending champion David Ferrer was pushed to three sets by Czech Lukas Rosol in his opening match at the Paris Masters on Wednesday before easing into the last-16, 6-0, 2-6, 6-3.
Rosol, who is part of his country's squad to face Serbia in the Davis Cup final on November 15, appeared to be on the receiving end of a rout before fighting back to give Ferrer a scare when he won the second set 6-2.
However, the experience of the 31-year-old Grand Slam finalist proved decisive in the final frame as Ferrer consistently put pressure on the Rosol serve and was rewarded with a third round tie against Frenchman Gilles Simon.
The Nice native, a semi-finalist loser last here in Paris against Poland's Jerzy Janowicz, defeated Nicolas Mahut in a marathon 6-4, 6-7 (5/7), 7-6 (7/3) second round matchup.
Simon led 4-1 in the final set before an injury break forced upon Mahut appeared to revive the taller Frenchman.
However when the conclusion went to a tie-break, it was Simon who was strongest and finally closed out the longest match of the tournament for a rewarding victory.
"It was very difficult for both of us and we both had problems," said a relieved Simon.
"It's the last tournament of the year and we're ready to die out there but I'm very, very happy to have won this match.
"I had lots of chances to win, I'm tired, I'm in pain but just very happy to have won," Simon told a vibrant crowd that pushed the players to their limits.
Earlier on court one, big-serving American John Isner bombarded Polish qualifier Michal Przysiezny with 27 aces on the way to a 7-6 (7/3), 4-6, 6-3 second round win.
Awaiting the US number one is six-time Grand Slam winner Novak Djokovic, who wrapped up his opening victory just after midnight on Tuesday, when he ended French qualifier Pierre-Hugues Herbert's fairytale run in straight sets.
Rafael Nadal makes his much anticipated tournament debut later on Wednesday against fellow Spaniard Marcel Granollers, while his long-time rival Roger Federer is also in action.
The Swiss record Grand Slam holder, needs just one more victory to seal his place at next month's ATP World Tour Finals for the 12th straight season.
Standing in his way is South African Kevin Anderson who advanced on Tuesday when Russian veteran Mikhail Youzhny retired in the third set injured.
Argentina's world number five Juan Martin Del Potro takes to the centre court against Marin Cilic after the Croatian capped his return from a doping ban with a first round triumph.
Federer's Davis Cup partner Stanislas Wawrinka faces a nervous match as he tries to close in on his place in London against Spaniard Feliciano Lopez.
The 28-year-old from Lausanne is not only trying to finish the year inside the top ten for the first time, but also protect his eighth place ranking and a maiden appearance in the English capital.
Canadian number one Milos Raonic faces a must-win situation in a bid to overtake Gasquet, Wawrinka or Federer and gatecrash the World Tour Finals but must get past Dutch qualifer Robin Haase first in the final evening matchup.
The powerful serving, Montenegro-born 22-year-old, must reach the final in Paris to have a chance to qualify.