Lewis Hamilton's celebratory moments as he became a triple world champion on Sunday had a bitter tinge.
As he equalled his boyhood hero Ayrton Senna's title tally at the end of a dreary weekend in Austin, Briton Hamilton said it was the best moment of his life.
But in the moments before he leapt for joy on the podium, his Mercedes teammate Nico Rosberg hurled a Pirelli-branded cap at Hamilton.
"The cap (incident) was nothing," the German insisted. "Just typical games."
In the pre-podium waiting room, an emotional Hamilton had helpfully tossed the second-placed Pirelli cap from the official table onto Rosberg's lap -- and the defeated German did not appreciate the gesture.
When it came hurling back, narrowly missing Hamilton's face, the new triple world champion glared back in surprise, and a similarly grim look could also be seen on Mercedes chief Paddy Lowe's face.
Rosberg then refused to spray champagne on the podium as Hamilton celebrated his win and title.
"We said before the race that Nico is always so controlled, but now the collar bursts," Marc Surer, a pundit for German television Sky, said.
"I think it was a completely normal reaction after this race and it should not be overstated."
Indeed, not only had Rosberg lost the world championship to Hamilton for the second consecutive time, he also lost the race win by spinning.
"It's unbelievable," he said of the latter. "It's never happened to me (like that), ever. Not even in testing, never. I can't explain it."
And, having started from pole, he was also furious at Hamilton for their first-corner clash, which he described as "very aggressive".
"Lewis just was too aggressive today," he added. "Extremely aggressive. One step too far. That's not ok."
Interestingly, while all sides admitted that Hamilton was the deserving champion, even Mercedes' team management admitted the first corner clash was not fair on Rosberg.
"Lewis left Nico no room at all and they even touched," said team chairman Niki Lauda. "You have to understand Nico if he is angry," he told German television RTL.
"But he also could have won the race, so although we are talking about the situation with Lewis, I think the mistake which was his (Rosberg's) fault hurts ten times more.
"But the manoeuvre at the start, he's absolutely right. Lewis also understands that and apologised. These things happen."
Toto Wolff also defended Rosberg, saying Hamilton's move was "probably a bit too hard".
"But this is not the time to criticise him," said the Mercedes team boss. "He is the world champion and a deserving world champion.
"We will return to the other theme in a few days and ensure that it doesn't grow into something bigger."
Bahrain International Circuit - Winter testing
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