Insisting that a podium finish was his for the taking, George Russell blames himself for the error which cost him vital points.
While his teammate soon got to grips with the various upgrades to the W14, Russell had pretty much struggled all weekend, consequently come qualifying he could only manage eighth.
Starting the race on hards, his afternoon didn't get off to the best of starts when he found himself under investigation for being in an incorrect position on the grid, though the stewards ultimately opted not to penalise him.
When Hamilton, Ocon and Sainz pitted on successive laps from Lap 31, Russell found himself in fifth, improving to fourth when Leclerc pitted on Lap 44.
With Gasly pitting on Lap 47, Russell had moved up to third and it was shortly after that the rain began to fall.
One of the few drivers, like Max Verstappen, to make a single stop whilst switching from slicks to Inters, things were looking good for the Briton who rejoined the race in fifth.
A slow second stop for Ocon and a spin for Sainz, only added to Russell's confidence that a podium finish was on the cards, however a mistake at Mirabeau, just moments after Lance Stroll had gone off at the same corner, proved costly because other than the time lost in rejoining the circuit, as he came back on to the track he clouted Sergio Perez, thereby incurring a 5s penalty.
"I'm really kicking myself," he subsequently told reporters, "because P3 was almost guaranteed after not pitting (early).
"I came out, and there was a yellow flag, I backed off and as soon as I touched the brakes I locked up and followed Stroll up the escape road," he sighed.
"That's probably a lesson when you're not on it and you're not focused you make those mistakes. If there wasn't a yellow flag there I would have been focusing more and wouldn't have gone off. I cost the team a comfortable P3.
"It's bitterly disappointing when you do everything right for 98% of the race but that one tiny mistake costs everything."
Russell, who at one point asked to be allowed to pass his teammate - insisting he would subsequently hand the position back - in a bid to cover off a closing Charles Leclerc, only to have his request denied, says the TV coverage doesn't show how close he came to a podium finish.
"I actually learned my mistake wasn't shown on television until a replay after the race," he said. "I don't think it was actually clear to people that we were effectively P3 on track and lost it.
"A lot of people texted me saying 'well done on P5', not realising I made a big mistake and cost us P3.
"I was being held up by Ocon and Lewis and Charles was closing me down," he said of his request to the team, "I definitely wasn't going to risk anything on Lewis in conditions on a circuit like this. But with that five-second penalty it would have been a good buffer if Charles had caught us up. But not needed in the end. I said to the team, no obligation, no pressure from my side. But something to consider."
"George shouldn't be too hard on himself," said Toto Wolff at race end. "He drove a nice first stint to have the opportunity to capitalise on the rain.
"The conditions were just so tricky to drive that a small mistake cost him quite dear but this was an afternoon where the team worked well, and our drivers showed their quality too, and that shows in the points scored."
"George was in a similar race with one Ferrari and one Alpine," added Andrew Shovlin, "we decided against the undercut and were waiting for rain, a safety car, or a red flag.
"That came," he continued, "but the transition was tricky. Only half the track was wet, but where it was, it was really damp. We seemed to make the switch at the correct time, but George got caught out with a lock-up during the warm-up phase.
"Luckily he continued, but our chance of a podium had evaporated. He did a good job to build enough of a gap to the Ferrari of Leclerc that his penalty didn't affect his position when it was added after the race."
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