Rookie Francesco Bagnaia thinks he has only understood 65% of what it takes to become a MotoGP rider, but that was still good enough to finish second fastest - under the all-time lap record - during this week's official Sepang test.

The #63 put his Pramac Ducati just 0.063s behind factory Ducati's Danilo Petrucci, courtesy of a 1m 58.302s lap time.

"For sure, I was not expecting to make a '58. My objective was '59 and to make a '58 and beat the [old] record is incredible," grinned the reigning Moto2 champion, who has a 2018 spec Desmosedici and received last year's fairing update on the final day at Sepang (pictured).

"I still need to improve a lot of things, but I'm very happy with the work done in these days because I understand a lot more.

"Most of all about how to ride a MotoGP bike, like a MotoGP rider. Making the racing line and especially the acceleration like a MotoGP rider."

How far along the MotoGP learning process does Bagnaia think he now is?

"At the moment I'm about 65%. Because I understand a lot more now, but you only get points in the race and I have to understand how to be more constant with used tyres.

"I'd like to win the car for qualifying this year, but with Marc it's very difficult!"

Bagnaia explained that he had taken big steps in ditching the flowing Moto2 riding style for a hard braking, lift-up-the-bike-and-go technique needed in MotoGP.

"The first day I was riding more similar compared to last year [in Moto2], with more mid-corner speed, and it has been very important to understand how to pick up the bike and use more traction on the exit," he said.

"One other thing where I improved a lot is in the braking, because last year in November and the first two days here it has been difficult, but we made a good set-up of my bike and I'm very confident with the front, which is very important for me.

"I prefer to have a good feeling with the front than the rear and in this moment I think we are in a good way, to have a good base to start the test in Qatar and to understand more things."

Next on Bagnaia's to do list is how to keep his pace with used tyres.

"I still need to improve in a lot of things. I have to understand how to be more constant with used tyres, but this morning has been another step because I started with used tyres and I made '59.9 in the first exit.

"That has been very positive, but for the race pace I need to improve a little bit more because the tyre drop in the race is different. Bigger. And I have to understand how to use the different engine maps as the tyre grip drops."

A local curry with @motomatters, @pecinogp and @Scherazade02 to finish the Sepang test. Lots of discussion about lap times beyond one fast lap. Pace shown by Marquez on day three was a surprise. Race lap record is a 2m 0.6s.#SepangTest #MotoGP pic.twitter.com/0hvhUxj1bO — Peter McLaren (@McLarenMotoGP) February 8, 2019

Despite finishing a whopping 12 places higher than next-best rookie Joan Mir (Suzuki), Bagnaia won't be changing his goals for the season ahead.

"No, I think I made a good lap and also a good pace but I prefer to be calm, work step-by-step and arrive in Qatar with the same objective, which is to be the rookie of the year.

"It hasn't changed anything at the moment."

Team-mate Jack Miller, on the GP19, was 0.064s behind Bagnaia in third.