(Reuters) -Ducati's Jack Miller edged out team mate Francesco Bagnaia to claim his first MotoGP win in five years at the Spanish Grand Prix in Jerez on Sunday.
Australia's Miller used his Ducati's power to pip pole-sitter Fabio Quartararo off the start line, with the Frenchman slipping to fourth behind Petronas Yamaha SRT's Franco Morbidelli and Bagnaia on the opening lap.
Quartararo, who won both the races in Jerez last season, recovered over the next two laps to regain the lead and began to stretch his advantage to up to two seconds at the top.
However, the Yamaha rider was struck with an arm-pump problem that saw his pace drop significantly, allowing Miller to regain the lead with less than 10 laps remaining.
As Miller continued to build his advantage to over 1.5 seconds, Quartararo plummeted down the order as he was overhauled by his championship rivals.
"I had a big issue with the arm, so sad because I was feeling really easy in the front," Quartararo, who finished 13th, told reporters.
"We had amazing pace this weekend and then I just had no more power on the arm. Just so disappointed about it."
Quartararo, who underwent an arm-pump operation on the same right arm during his rookie season in 2019, said his team was evaluating options for him ahead of the French Grand Prix on May 16.
"It's something I don't understand," he added. "My brain is full of people telling me to go in one place, to go to the other. And actually right now I'm lost."
Miller held off Bagnaia to take the chequered flag for the first time since winning the 2016 Dutch Grand Prix, while Morbidelli rounded out the podium.
"It's just indescribable what I'm feeling right now," said an emotional Miller. "I had done a lot of laps by myself this weekend and I knew I had reasonable pace.
"After Fabio took the lead, I didn't expect him to come back to me but he did.
"When I got past him, I just kept my head down and got as much as I could out of the last seven-eight laps - which felt like the longest I've ever had in my career."
Bagnaia now leads the world championship with 66 points, two clear of Quartararo.
(Reporting by Hardik Vyas in BengaluruEditing by Toby Davis and Pritha Sarkar)