The Ducati rider has won five of the last nine races plus three further podiums (and a fifth non-score of the season).
But the title would have remained out of reach had Quartararo not also suffered four non-scores and only two podiums over the same period.
Reigning champion Quartararo must now win Sunday’s Valencia race and then needs Bagnaia 15th or lower to prevent the Italian claiming the title.
On the eve of the finale, six-time MotoGP champion Marc Marquez was asked if he felt Quartararo had ‘lost’ the title in the second half of the season or if Bagnaia had gone out and ‘won’ it.
“You can choose both ways,” Marquez replied. “Because Fabio did a lot of mistakes, but Pecco won many races.
“Pecco did an amazing second part of the season, that he did last year already. But last year, Fabio was constant and he managed his advantage.
“This year Pecco did the same thing. Amazing second part of the season, even better than last year, but Fabio was more inconsistent. But what I say is that Fabio, what he did in the first part of the season was more than the level he had [from] the bike.
“So he put that extra and then Pecco put that extra in the second part of the season, plus the bike [Ducati] for me is working better than the Yamaha.
“But both of them deserve it. And especially the way that Pecco managed the Malaysian GP is not easy. It’s not easy when you are fighting for a championship. So yeah, [Bagnaia] has the level to be champion of course.”
Prior to Sepang, Marquez spent much of the Phillip Island race locked onto Bagnaia’s rear wheel.
“The strongest point of [a rider] is always combined with their bike,” Marquez said.
“Because the strongest point of Fabio is corner speed but it’s combined with the bike. Then Pecco, they had a really good bike to take profit with the new tyre and especially to manage the race with a group.
“Because they have an amazing engine, the fastest of the grid. And they have also very good braking stability. So they are braking so late. Corner speed is not amazing, but acceleration is so good so then it’s very difficult to overtake.
“But as I saw in Phillip Island, is not everything amazing with the Ducati bike. Also the corner speed was slower than mine and especially Suzuki also had much better corner speed than the Ducati.
“So then you need to find a compromise and as a rider, be smart and take the profit of your bike and adapt to your bike and he [Bagnaia] did very well and he’s riding very very good.
“Whoever is the best rider in MotoGP 2022 will finish the [Valencia] race and be champion.”