French champion Fabio Quartararo extended his lead after winning the Catalonia MotoGP on Sunday.

The Frenchman's joy contrasted starkly with Aprilia rider Espargaro, who had a nightmare of a race from start to finish.

Having started on the pole, he was passed by Quartararo on the first bend – a lead the 23-year-old Frenchman would never relinquish – and then, as the race reached its climax, he raised his arms, thinking he had finished second only to realize there was a still a lap to go.

"The only thing I can say is 'sorry' to my team," said a contrite Espargaro.

"It is an inadmissible error at this level of competition.

"It is totally my fault. I completely forgot that here the last lap is listed as zero, not one, hence I took my foot off the gas in the finishing straight.

"If I am to beat Fabio in the title race I cannot make such errors."

His misfortune allowed compatriot Jorge Martin to take second with his Ducati Primac team-mate Frenchman Johann Zarco taking third.

Quartararo increased his lead from eight points to 22 after nine rounds of the championship.

Little wonder he bore a broad grin on his face as he climbed off his Yamaha -- who he committed to for an extra two years on Thursday.

"I am so pleased, this was an incredible race," said Quartararo.

"I pushed hard from the start and kept it up to the finish.

"With this win and my second place in Mugello last Sunday, these are two great results as I feared the worst beforehand.

"Life is good, we have worked hard."

Martin was delighted with his second spot after a largely disappointing season.

"It has been a tough season so I am delighted with this podium finish," said Martin.

"I thought I would find it hard to finish with one of my tires giving me trouble so I just conserved my energy.

"Then I saw Aleix slowing and I thought he had a mechanical problem but then realized he had made a mistake.

"That was an unexpected bonus."

'Put my foot down'

Zarco too reflected on his good fortune, though, timely as it is expected he is set to extend his contract with Ducati-Primac.

"That was a bit lucky with what happened at the end of the race," said Zarco.

"I did not expect that! I was very tired as the race came to a close. I saw him (Espargaro) raise his arms and there was little doubt in my mind maybe the race was over."

"However, I saw Martin was still racing at full speed so I put my foot down."

Even better for Quartararo was neither of his Italian rivals who loom large in the championship standings finished.

Francesco Bagnaia – who won the Italian MotoGP last weekend – slipped to fourth in the standings behind Zarco following his first bend exit.

Bagnaia's Ducati came crashing to the ground after Japanese rider Takaaki Nakagami fell and his helmet connected with the Italian's bike.

Bagnaia slid across the track and took out Alex Rins on his Suzuki – fortunately, all three were reported to be ok.

Bagnaia's compatriot Enea Bastianini also finished his day early coming off with 17 laps to go pon his Ducati-Gresini, the Italian hitting his knees in frustration.

He remains third in the standings with 94 points.