A 'green' track from the rain showers that hit the Singapore Grand Prix, allied to cooler temperatures, is the likely explanation for why Mercedes' form turned around so dramatically on Sunday.
But a downpour shortly before the start, and an opening lap crash that put both Ferraris out, opened the way for Hamilton to seize the lead and go on to take a crucial victory.
The win was not just about the first lap though. Hamilton showed strong pace against the pursuing Daniel Ricciardo throughout, with teammate Valtteri Bottas even able to close in on the Red Bull driver near the end.
Bottas said that from inside the cockpit, a greater feeling of stability from the rear of the car resulted in greater confidence in pushing the car – which was turned into quick laptimes.
"In terms of the rear stability of the car, it was much better in the race than any point of the weekend so far," said Bottas. "That was the reason for the pace.
"There were cooler temps, some damp patches still on the track, so I think definitely the cooler temps helped us and me as well. I think it really actually meant I could lean on the car more, so it came from the rear stability."
But the cooler temperatures are not the only explanation, for race day was not that much colder than the track had been in the practice or qualifying.
It seems like that other circuit conditions played into the team's hands too.
A wet start was great for Mercedes, for as well as it allowing Hamilton's talents to shine, the team's W08 car has proved strong on the 2017 intermediate tyres.
Although engineers are not sure why – it could perhaps be related to a change of ride-height characteristics that come when you move off slick tyres – a previous deficit to Red Bull on the inter has been wiped away this year.
Then as the track dried out, circumstances again worked well for Mercedes.
The first factor was that Ricciardo was stage suffering from a minor gearbox problem. Team insiders suggest it cost Ricciardo half-a-second per lap.
And despite the Australian saying after the race that he did not believe that even a fully functioning Red Bull would have been enough to beat Mercedes, it certainly meant Hamilton was under less pressure at the front.
The second factor was that when drivers switched across to slicks, the Mercedes remained strong because grip was still low.
It proved faster than the Red Bull on the 'green' track with the rubber having been washed away, and the cooler temperatures meant the tyre overheating problems that hit the car's balance in qualifying were not there.
One theory is that the Mercedes is a better car when circuits have very little grip – as is witnessed so often when Hamilton and Bottas are so fast in first practice.
"It was a nice reset with the rain that came in, which dropped the grip level, I think.
"And then obviously being Intermediates to start with, still even in that scenario, I thought they would be a lot closer pace-wise but… yeah, these conditions, as I said, I love, and it's very much an opportunity to really make a difference with your driving in those conditions, and today I was really able to."
Mercedes boss Toto Wolff was in no doubt that the swing in form was down to tyres, and more specifically how the team was able to manage them better in the race.
"Tyre temperatures," he said. "We were running always in a zone where we had the tyre temperatures under control and in qualifying it was hotter.
"In order to extract it on one lap you need to run them higher. The track was green. The grip was less than in qualifying yesterday and it was cooler and less push"
Despite the success, however, Wolff thought it vital his team worked on understanding its performance over the weekend.
"It's such an interesting analysis to be done, because every year we come to Singapore and we struggle," he said.
"Last year we won 19 races and albeit we won the race it was a difficult weekend for us. I looked at the qualifying results from 2015, we were 1.5s off the pace in P5 and P6, so I think there is no need to panic.
"We can keep calm because the top 10 yesterday in qualifying were exactly the top 10 of Hungary. It is a track layout that doesn't suit us, and we have to understand why.
"It's what we've done the last years after Singapore, and then concentrate on the next ones."