Ducati’s Francesco Bagnaia put in a sure-footed display at a rain-drenched Buriram International Circuit as he romped to victory in the Thailand Grand Prix on Sunday and slashed his gap to championship rival Jorge Martín down to 17 points.

Reigning champion Bagnaia took advantage of errors by Pramac Racing’s Martín and Marc Márquez of Gresini Racing to take the chequered flag and clinch his ninth win of the season. Martín finished second while GasGas Tech3 rookie Pedro Acosta was third.

“This morning after the warm-up, I wasn’t that happy, but I want to say thanks to my team,” Bagnaia said. “We looked at the data, we understood what to do. There was more water on the asphalt and it was better for me. I’m so, so happy.”

Martín’s second-place finish moves him up to 453 points while Bagnaia is second in the standings on 436, with two races left – in Sepang next weekend and Valencia a fortnight later.

Italian Bagnaia began the race in pole but Martín took the lead heading into turn one with a trademark rocket start. However, the world championship leader, who had trouble navigating the treacherous conditions and could not find his best form on the slick tarmac, ran off track on the fifth lap and handed the advantage to the two-times champion.

Martín’s mistake dropped him down into third behind Bagnaia and Márquez, and he was forced to be content with staring at the plume of water kicked up by Márquez’s rear tyre for the next few laps.

Asked about racing in the rain, Martín said: “The level we are demonstrating, I think, not a lot of people can understand how fast are we going, even with these conditions.

“Today was a tough race. I started really good, but then I was taking a bit of a risk. I went wide in corner three. After that, I just tried to be close to Marc and Bagnaia. I had a lot of moments. The grip was really poor. I was struggling a lot.”

Six-times world champion Márquez stepped on the gas midway through the race and quickly moved within half a second of Bagnaia, setting off alarm bells for the Ducati rider. Bagnaia was able to thwart the Spaniard’s attempts to dislodge him from the lead and Márquez crashed on the 15th lap.

By the time Márquez crashed, Martín had already lost ground on Bagnaia and there was little he could do to prevent the Italian’s win.

“When Marc crashed, I was still trying to catch Bagnaia, but I saw I was too on the limit,” Martín said. “Then I said to myself: ‘OK, it’s time to finish second again.’ I let him win.”

Márquez was able to climb back onto his bike and rejoin the race, finishing 12th.

Enea Bastianini, who won Saturday’s sprint, started in second but immediately dropped down a number of places after a poor start, before crashing and ultimately finishing in 14th.