MotoGP world champion Marc Marquez said he was "unlucky" after a damaged wheel forced him out of the season-opening Thailand grand prix late in the race on Sunday.
The Spanish Ducati rider is launching his bid for a record-equalling eighth world title, but he exited the race in Buriram in dramatic fashion while in fourth place with five laps remaining.
Marquez had his sights on catching Pedro Acosta and Raul Fernandez, but he took a corner wide and punctured his tyre and buckled his wheel as he went off the course.
Marquez said he was "riding in a safe way", but he had to watch from the team garage as Aprilia's Marco Bezzecchi took the first grand prix win of the season.
"I was unlucky because that curve I jumped a hundred times in the test or during the practice, and it never happened what happened now," Marquez told reporters.
"Normally, curves are made that you can jump out in a good way, you need to be careful when you jump in.
"So I jumped out, but when I jumped out I felt, already, that the rear tyre exploded with a big hit also on the rim."
Marquez dominated last year's championship, but he said earlier this week that he was still feeling the lingering effects of a shoulder injury that forced him to miss the final four races of the season.
He started from second on the grid, but he was picked off by a succession of riders until he managed to haul himself back into podium contention.
"The first part of the race I was trying to manage my physical condition and also the tyres, but then when there were 10 laps left, I gave everything, and then I was closing the gap," said the 33-year-old.
Bezzecchi led from start to finish from pole position to win the race ahead of KTM's Acosta, with Trackhouse's Fernandez third.
Acosta won Saturday's sprint ahead of Marquez, after the defending world champion was forced to let him pass on the final lap because of a penalty.
Ducati finished the grand prix off the podium after Marquez's teammate Francesco Bagnaia finished ninth.
Bezzecchi won all three practice sessions in Thailand and set a new track record in qualifying before he crashed out of the sprint on the second lap.
"We understand, already, second part of the season last year Bezzecchi won many races and it looks like the others are getting closer and closer," said Marquez.
"But we are working, and let's see – let's understand the next races where we are."