Fabio Quartararo twice smashed the lap record in practice for Petronas Yamaha SRT's home race but says he will need to go even faster in qualifying for the Malaysian Grand Prix if the rain stays away.
Quartararo set a new quickest circuit of one minute 59.057 seconds in FP1 on soft tires in Sepang on Friday – then bettered that time with a 1:58.576s lap in the second session.
The Frenchman's teammate Franco Morbidelli was second-fastest, with Ducati's Andrea Dovizioso in third following two dry sessions.
Quartararo said a dream start will count for nothing if Petronas Yamaha are unable to deliver when it really matters.
"It is only Friday so for sure in qualifying - if it's good weather – we will need to be [faster] again to make the front row. I'm happy to do the lap record, but it will be better to do in qualifying and then fight for the race," he said. "Phillip Island was really tough and did not go like we expect; two crashes, one on Friday and another at the beginning of the race, so we arrived here with not a lot of confidence, but we already made first in the morning and then the afternoon also.
"The confidence came back, which is good for tomorrow."
The 20-year-old added: "I think we need to be smooth with this bike, but there is a balance between really smooth and aggressive. We need to find the right balance to suit the Yamaha and I think we did it."
World champion Marc Marquez finished FP2 in sixth position following an issue with his bike in the first session.