PARIS - Marc Marquez's rivals are aiming to take advantage of the uncharacteristic layout of the Bugatti circuit at Le Mans and unpredictable weather conditions as they seek to halt the Spaniard's early-season domination at the French MotoGP on Sunday. Defending champion Marquez, who on Thursday penned a two-year extension with Honda through until the end of 2016, has won all four races this campaign - a victory on Sunday would see him match Italian great Giacomo Agostini's five straight wins to open the 1972 season.However, the 21-year-old sounded a note of caution, acknowledging there would likely be times when things wouldn't go his way. "From now onwards, I must think that there are circuits where we won't be able to win. When we get to this level, we think we can win everything but we're going to have to start managing things," Marquez told AFP on the back of his triumph at the Spanish Grand Prix.Marquez has finished on the podium in 20 of his 22 MotoGP races, notching up ten victories to date but has yet to triumph in France. He finished third in his debut at Le Mans a year ago and will need to find a way to combat a circuit that is often plagued by wet, chilly conditions and renowned for its stop-start nature where the majority of the four-kilometre track's 13 turns are performed at low speeds.With that in mind the performance of his bike will come under close scrutiny during braking sections, while attaining maximum grip coming out of the turns is also likely to be crucial. Despite finishing on the podium in all four races this term Dani Pedrosa, who's second in the standings, finds himself already 28 points behind Honda teammate and compatriot Marquez. Pedrosa won at Le Mans for the first time last season and is hoping he won't suffer any lasting effects after undergoing surgery to relieve problems caused by arm pump.As for the Yamaha contingent of Valentino Rossi and Jorge Lorenzo, both harbour goals of repeating past glories in France as they seek to claw their way back into the title picture. Rossi has nine premier class podium finishes at Le Mans, including three victories, and wants to build on his second-place finish at Jerez a fortnight ago. "I made good times during the (post-race Jerez) test, even the 'time attack' was good and so I will try to start from the front row at Le Mans. "It's a positive moment for me because I'm pretty fast, I work well in the box and I think we can be very optimistic. We can have a good race," said the Italian. Two-time world champion Lorenzo is also a three-time winner at Le Mans but has endured a sluggish start to the season, leaving him fifth, a staggering 65 points adrift of Marquez. "Right now I am just thinking race by race and not about the championship," admitted the Spaniard, who has just one top-three finish this term. "The weather will play a big part, usually it is colder and can be tricky like it was with the rain last year. The asphalt can be slippery but I am confident we can manage the circumstances and get a good result."