Fernando Alonso furious as brake issue sees Lewis Hamilton runs wide four times in a single lap.
Having made a late stop for softs it appeared the gamble might pay off for the seven-time world champion. Pitting on Lap 46 from seventh, he rejoined without losing position, well clear of Alonso who had just passed Liam Lawson.
As he caught his Ferrari teammate, who was told to yield, Hamilton set about taking on Kimi Antonelli for fifth, however in the final stages of the race he began to suffer a brake issue.
As Antonelli disappeared into the distance, Leclerc closed in and passed the struggling Briton three laps from the end.
Alonso was still some way behind but such was Hamilton's brake problem that the Spaniard was reeling him in.
On the final lap, due to the issue Hamilton exceeded track limits at Turns 2, 5, 16 and 17, and somehow held off the charging Alonso by 0.416s - not that we got to see it because the TV broadcasters had cut to the McLaren celebrations.
Needless to say, Alonso was not happy.
F****** hell man, I cannot believe it," he declared over the radio. "I cannot f****** believe it... is it safe to drive with no brakes?"
Hamilton was subsequently handed a 5s penalty that dropped him to eighth and promoted Alonso, however the penalty was for the number of track limits violations, not driving his car in an unsafe condition.
"It's pretty gnarly," said the seven-time world champion. "I got onto that soft tyre and I was attacking to close that 22-second gap or whatever it is.
"I saw my brakes were getting hot, but they didn't say they were at the max, and as I went into Turn 14, sparks came off and my pedal went long and I'm just so grateful I made the corner.
"When I started braking for those corners, I just had to cool the brakes and I wasn't getting a lasting advantage of cutting, and also I didn't know if anyone was braking deep behind me so I wanted to get out of the way.
"I don't know how that (P7) was possible," he admitted, "but keeping Fernando behind at the end was really really hard."
Team boss, Fred Vasseur was keen to play down talk that the brakes were a safety issue.
"We adapted the pace," he said. "It's not that Lewis was pushing like hell in the last lap, but he was thirty seconds slower.
"In terms of safety, it was on the safe side, but not the target. The target is to be safe, but the target is not to be safe," he smiled.
Alonso had been one of the highlights of what proved to be a somewhat processional race, enjoying skirmishes with a number of drivers that saw him dig deep into his wealth of experience.
"Trophy for the hero of the race," he declared following a thrilling duel with Isack Hadjar, while subsequently, told the number of laps remaining, he warned: "If you speak to me after every lap, I will disconnect the radio."
It's unclear if the "hero" comment referred to himself or was a dig at Hadjar following the RB driver's dogged defence of his position which at one point almost saw the pair come to grief.
"I mean, I didn't push him off the track," said Hadjar at race end. "I kept it clean. If he didn't enjoy that fight, then he's really grumpy and there's nothing I can do for him."
"I think he had a little bit of an engine problem, from what I understood, on the straights he was slow," said the Spaniard. "Sometimes, some battles you need to know when it's better to fight, when it's not, because probably the final result of the race could be worse for both for sure, but for him in particular.
"So yeah, I think some unnecessary risk, but I understand that this is Singapore and you need to fight hard, and he did his best, but we lost time for sure."
Told about Hadjar's "grumpy" remark the Spanish veteran replied: "Well, some movements at 300km/h are a little bit borderline in Singapore, but everyone races as they want and there was no contact, nothing like that, so everything is fine. They have a very fast car, they don't have many points, so it's more their problem."
Good to see the Samurai as feisty as ever.
Check out our Sunday gallery from Marina Bay here.
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