Honda's Marc Marquez took another significant stride towards a sixth MotoGP title by seizing victory in a last-lap duel at the San Marino Grand Prix on Sunday. The Spaniard moved 93 points clear at the top of the standings with six races remaining after denying French Petronas Yamaha rookie Fabio Quartararo a first top-flight victory at Misano's Marco Simoncelli circuit. Yamaha's Maverick Vinales finished third. Marquez's closest championship rival Andrea Dovizioso, on a Ducati, was only sixth. Marquez now has 275 points to the Italian's 182.