Valentino Rossi's feud with Marc Marquez continued in Valencia as the Italian accused the Honda rider of allowing Jorge Lorenzo to win the season finale.
Despite heading to Spain trailing Rossi by seven points in the Championship standings, Lorenzo claimed the crown by five points thanks to his win in Valencia coupled with Rossi's P4.
Lorenzo raced unchallenged from lights to flag as never once did Marquez launch any sort of attack despite spending the latter laps right on the Yamaha rider's rear wheel.
Rossi believes that is because the two Spaniards colluded ahead of the final race of the MotoGP season.
"Today everyone has seen their plan, this makes me sad and it's a very bad thing for our sport," the Italian told Motorsport.com.
"I do not understand why a Honda rider allows Yamaha to win [the MotoGP race]. I hope this behaviour in time turns against him.
"Lorenzo is a very good rider, it would be nice to battle on equal terms, but I think even he wouldn't be very happy to have won like this."
The seven-time MotoGP Champion, who started Sunday's race from the back of the grid after being penalised for kicking Marquez into retirement at the previous race in Sepang, even went as far as to say the Honda rider acted as Lorenzo's "bodyguard.
He stated: "I am sad that Marquez acted as bodyguard for Lorenzo. I had already said on Thursday, I was convinced that they would go to the end [with their plan], I was sure they would have conspired against me.
"I don't know if Marquez protected Lorenzo because they are both Spanish, but it's sad he chose to be his bodyguard. Lorenzo has never done what Marquez did. But for his behaviour after Malaysia [when he attempted to join the court proceedings], he deserves to be treated like Marquez.
"I'm sad, a great opportunity has vanished and I did not deserve this."