Valentino Rossi was left distraught after seeing the chance of a first race win of 2018 slip away in Malaysia on Sunday.

With Marc Marquez jettisoned to seventh on the grid for a qualifying incident with Andrea Iannone, Rossi was able to surge ahead in Sepang after a stunning start.

The Italian quickly left Johann Zarco behind and opened up a commanding lead, with Marquez fighting his way back to second in the latter stages.

Catching Rossi still looked like a big ask for Marquez but the world champion was gifted victory when the seven-time champion crashed out at the first corner with four laps remaining.

And that left Rossi, who has not won a race since Assen in June 2017, "devastated".

"We have to say that is my first mistake of the season because I arrive always at the end, except in Argentina," said Rossi.

"Maybe it is the worst moment [to make the mistake], I am devastated for the crash.

"On the other side I am also happy because anyway we live the dream for 15 laps, and after the victory of my brother [Luca Marini in Moto2] also could've been a great day, but it's like this.

"For one side I am very happy for the race because is the best race of the season for me and is also coming in difficult condition and in a difficult track for us. This is very important.

"On the other side is a great shame, I am very disappointed for the mistake and make a race like this and go home with zero point is frustrating."