Valentino Rossi says he felt "cheated" after losing the French Grand Prix to Yamaha team-mate Maverick Vinales.
Rossi appeared set for his first win of 2017, having taken first place from Vinales with three laps to go, but the Italian ran wide on the final lap to let his teammate back through before crashing out as he attempted a last-ditch attempt to pass.
The Doctor's ire was prompted by Vinales running off-track on the penultimate lap, rejoining the track on Rossi's tail.
Rossi's frustration may have been compounded by Vinales' victory sneding him 17 points clear in the riders' standings.
"I did not see it, but he cheated me a little bit by cutting the track," said Rossi, who was given a 0.3-second penalty in the Grand Prix of the Americas for a similar infringement.
"I did a very fast lap - I think 1m32.3s - but he cut the track in sector three and caught back up to me when I had a little bit of advantage.
"If I passed the finish line four tenths ahead, maybe I would not have made the mistake.
"The rules however are like this, and in any case I still made the error."
On his crash as he frantically attempted a half-lap comeback, Rossi explained: "There are days when you feel you can win and you have to try, otherwise you're not at peace with yourself.
"I felt [I could win] and I tried. It was a stupid mistake, but it was still a good weekend, because I've never been so strong on this bike."
Despite Rossi's frustrations, Vinales insisted that cutting the corner did not give him the necessary advantage to put crucial pressure on his team-mate.
"When I did that, I lost a lot of time because I was right on the back of Valentino and then I was half a second behind," Vinales told BT Sport.
"It doesn't change anything, because finally I entered [the final lap] more far [behind Rossi] than I was."