Andy Murray has never made it past the quarter-finals in Paris in seven previous visits to the French capital at this time of year but on the evidence here so far this week, his luck may be about to change.

The US Open champion opened his account at the Palais Omnisports de Bercy with a confident 7-5, 6-3 victory over French veteran Paul-Henri Mathieu last night while his biggest rival for the title, Novak Djokovic, was surprisingly beaten 6-0, 6-7, 6-4 by American Sam Querrey.

With next week's Barclays ATP World Tour Finals uppermost in his mind, over-extertion is not an option this week but with Roger Federer and Rafael Nadal absent and now Djokovic beaten, Murray will not get a better chance to narrow the gap on the top two and take even more confidence into London.

"I have played many tournaments where I have expected to play certain guys and certain rounds, and there are regularly upsets in tournaments so you don't play the guys you're seeded to be play," Murray said, when asked if he felt like the favourite. "It's just important to just try and focus on your matches and I'll need to improve on tonight's match if I want to do well here. But I served well."

World No.64 Mathieu was once ranked as high as No.12 before injuries set in and in the first set, with the help of the home crowd, he matched Murray from the baseline.

Murray saved a break point in his opening service game with an ace and every time he faced a hint of trouble, he served his way out, with 10 of his 12 aces coming in the first set alone.

His recent decision to take up pilates to ease his sore back seems to have made his serve even looser and after breaking for 6-5, he saved two break-back points to close out the opening set.

Stepping up the pace, the Olympic champion broke twice to lead 4-1 and though he gave back one of the two breaks, he held on to set up a clash today with Polish qualifier Jerzy Janowicz, who, at 6ft 8in., will present a different kind of challenge.

"I've been playing very well in practice and felt confident, but when the match started it's different conditions. I struggled with my timing. I've never played my best tennis here, but I'd like to change that."

What kind of shape Djokovic will be in come London is hard to evaluate after the Serb, who will regain the world No.1 ranking on Monday, was beaten by Querrey, despite winning the first eight games.

After celebrating Hallowe'en by walking on to court wearing a Darth Vader mask, his defeat marked the first time in almost two years that he has failed to make the quarter-finals of an ATP Tour event.

It is events off the court that are most worrisome, however. Reports in the Serbian press over the past few days said that Djokovic had flown back from Paris to Belgrade to visit his father Srdjan, who is in hospital being treated for an acute respiratory condition.

A news agency yesterday cited Djokovic's uncle, Goran, as saying Srdjan's condition is improving and "he is through the worst" but the winner of five major titltes did not want to discuss specifics.

"I [have] had a really difficult last couple of weeks," Djokovic said. "Some things happened and [there's] a lot of things on my mind and [things I] had to do, so right now I just need a couple of days' rest before London. I've travelled a lot, let's [put] it that way, even though I was here."

Djokovic is now likely to fly back to Belgrade before London begins and though he is sure to take his place in the eight-man field for the ATP World Tour Finals, his state of mind when he gets there is another matter.

In the past few days, Djokovic has been affected by illness himself and though he did not want to make excuses, after romping through the first set, his energy waned and he faded in the deciding set.

"I knew the main problem today would be the continuity of my energy," he said. "Unfortunately, it wasn't to be after the second set. During the second set I felt physically down, and I struggled every game.

"Right now, the way I feel, I definitely need a few days' rest, and then try to get a few days' practice before London starts."

Richard Gasquet's outside hopes of securing a place in London were ended when he was beaten 7-6, 4-6, 6-1 by South Africa's Kevin Anderson.

Jo-Wilfried Tsonga needs just one more win today to book his spot and Janko Tipsarevic, of Serbia, took a step closer to joining them as he defeated Igor Sijsling 6-4, 7-6 to reach round three.

The seventh-seeded Argentine, Juan Martin Del Potro, saw off the challenge of Colombia's Alejandro Falla 6-2, 6-2 while the ninth-seeded Spaniard Juan Monaco beat Bulgaria's Grigor Dimitrov 7-6 (7-4) 6-2.

Nicolas Almagro, the 11th seed, and Gilles Simon also progressed.