Valentino Rossi lost the 2015 MotoGP championship with his mistake at the Malaysian Grand Prix, according to his teammate Jorge Lorenzo.
Rossi was penalised for his incident with Honda's Marc Marquez during the Sepang race, where the duo were involved in a clash that ended with the Spaniard on the ground after contact with the Yamaha rider.
As a result of the penalty, Rossi started the Valencia finale from the back of the grid and could only climb up to fourth in the race.
Lorenzo went on to win the race and take the title by five points.
The Spanish rider believes without the Sepang incident, Rossi would have probably been champion.
"Valentino is a great champion and possibly based on his stats and for everything he's brought to bike racing the most important rider in the history of the sport," Lorenzo told Spain's Cadena Ser radio on Monday night.
"But we all make mistakes and at Sepang he made a mistake that possibly cost him the title."
Lorenzo insisted he is a worthy champion despite Rossi's claims that he was aided by Marquez in the last races.
"I'm trying to value what I've achieved and I think I'm the fair winner, based on the statistics and I also have more points," said Lorenzo.
"Each person will have their own opinion and it's hard to put in the other rider's situation and be objective.
"I guess if I were in his situation I would think the same, so I'm not judging his opinion."