19 places between the two title contenders after Vettel stopped by engine; Hamilton edges out Raikkonen, with Verstappen third
Lewis Hamilton claimed a brilliant Malaysia GP pole position to fully capitalise on Sebastian Vettel's latest title setback as the Ferrari driver qualified last amid engine woe.
Vettel and Ferrari had appeared favourites for pole after Mercedes struggled in practice, but the balance of power turned around spectacularly on another potentially decisive day in the 2017 world championship fight.
Vettel failed to set a qualifying time and will start 20th after his Saturday was wrecked by engine problems.
An electrical issue had first struck Vettel's car in final practice, and although Ferrari's mechanics impressively installed a replacement engine in the space of two hours, a turbo glitch then struck on the German's out lap in Q1.
Vettel's back-row start for Sunday's race comes just two weeks after he crashed out of the Singapore GP.
Hamilton is now perfectly placed to increase his 28-point championship lead after he pipped the other Ferrari of Kimi Raikkonen in Q3 for his 70th career pole.
Max Verstappen will start third after again out-qualifying Red Bull team-mate Daniel Ricciardo, who hung on to fourth ahead of Valtteri Bottas in the other Mercedes.
After lapping over a second off the pace on Friday, Mercedes split their drivers' set-ups for Saturday's action with Hamilton reverting to an older-specification aero package, while Bottas continued with the one introduced this weekend.
Esteban Ocon impressed on the way to sixth for Force India, with Stoffel Vandoorne beating Fernando Alonso (10th) at McLaren to claim a fine seventh for a career-best grid slot.
The four-time champion, who held a 14-point title lead just four races ago, was fairly phlegmatic about his latest disappointment and believes he can fight back in Sunday's race.
"It's part of motor racing," Vettel told Sky F1. "For sure, it's not ideal, it's not what we want, especially on a day where you feel that you've got it in you, you've got it in the car but we won't be able to prove that. It's a pretty bad day."
Conversely, it was an unexpectedly strong day for Mercedes and their championship leader.
Hamilton has now claimed nine pole positions this season - six more than any other driver - but said he was as surprised as anyone to be starting at the front again.
"We had such a difficult day yesterday it was difficult to know where we stood. I didn't sleep very well last night as we didn't know if we would fix the issue," he said.
"The car was better but it still looked like Ferrari were ahead. We had some decisions to make for Qualifying.
"That first Q3 lap I don't really know where it came from. I'm surprised to be up here."
Despite using the newer-spec package, fifth-placed Bottas lapped 0.682s slower than the sister Mercedes. The Finn has qualified more than half a second adrift of Hamilton at every race since August's summer break.
"Maybe we shouldn't underestimate the driving factor," said Mercedes chief Toto Wolff. "These cars are tricky to drive and ramping it up until this final section is important and he has been improving his driving all through the weekend like he did in Singapore."
"Honestly Ferrari are the only one who have shown consistent pace all weekend on long runs," Red Bull's Ricciardo, who will start fourth, said. "I think we've been not completely happy with ours, and I think Mercedes as well haven't found a good balance.
Raikkonen and Verstappen will line up in close company for the second time in as many races and the pair were in jovial mood after qualifying when reflecting on the spectacular start-line crash of Singapore.
"I don't want to be sandwiched," joked Verstappen about the race start, to which Raikkonen responded: "I don't want to be hit!"
Who will come out on top in Sepang? Watch the Malaysia GP live on Sky Sports F1. Race coverage starts at 6.30am on Sunday - with lights out at 8am.