MotoGP world champion Marc Marquez won the Japanese Grand Prix with a pole-to-flag ride on Sunday as Honda secured the constructors' title at their home Motegi circuit. The 26-year-old Spaniard had already made sure of his sixth MotoGP championship, and fourth in a row, a race earlier in Thailand on Oct. 6. The constructors' title was Honda's 25th, coming as the company celebrates 60 years in motorcycle racing. "It was not easy," said Marquez after his fourth win in a row and 10th of the season. "I was pushing from the beginning… with the fuel and everything I was on the limit." French rider Fabio Quartararo finished second for the non-works Petronas Yamaha team, 0.870 behind, to be sure of the MotoGP 'rookie of the year' accolade, with Italian Andrea Dovizioso third for Ducati. The podium was Quartararo's sixth top-three finish of the season but the 20-year-old is still awaiting a first win in the top category. His first lap attempt to get ahead of Marquez lasted only three corners. Marquez then led every lap as he made sure of his 54th victory in the top class, pulling him level in the all-time record books with retired Australian Mick Doohan. Quartararo came under pressure at the finish on fading tyres, with Dovizioso closing the gap but running out of time to make a move. The Italian could still celebrate his 100th podium finish. "It was a strange race. I think Quartararo maybe finished the tyre," said Dovizioso. "I was pushing so hard, a bit over the limit, because I really wanted second." Marquez has an unbeatable 350 points to Dovizioso's 231, with three races remaining in Australia, Malaysia and on home soil in Valencia. Honda have 356 points to Ducati's 270. Yamaha's Maverick Vinales was fourth with Britain's Cal Cruchlow seizing fifth at the line for LCR Honda from Quartararo's team mate Franco Morbidelli. Yamaha's Italian great Valentino Rossi crashed four laps from the end while in 11th place, and Marquez's triple world champion team mate Jorge Lorenzo finished only 17th and 40 seconds behind the winner.