Max Verstappen hit the track as a Formula 1 champion for the first time on Tuesday, with the Dutchman taking part in post-season testing less than 48 hours after he claimed the title in a race that continues to stir debate and drive scrutiny on the sport and its governing body.
Completing 124 laps around the same Yas Marina Circuit he overtook Lewis Hamilton on to win the Abu Dhabi GP and his maiden F1 crown, Verstappen was one of 19 - a combination of current and inexperienced drivers - who were testing the new 18-inch tyres in modified mule cars ahead of 2022.
He finished 17th on the timesheet, ahead of George Russell in the Mercedes - testing before his move to partner Hamilton next year.
Formula E champion Nyck de Vries topped the day in the Merc, while other notable participants were Valtteri Bottas and Guanyu Zhou - starting their Alfa Romeo partnership early - F2 title-winner Oscar Piastri in the Alpine and IndyCar front-runner Pato O'Ward for McLaren.
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- Hamilton said 'this has been manipulated' in radio message
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The annual end-of-season test, which will conclude on Wednesday with the final day of track action for 2021, is taking place amid continued controversy for the sport following an Abu Dhabi conclusion and result that Mercedes have lodged an intention to appeal.
They have until Thursday night to officially appeal - the same night Verstappen is due to be crowned champion at the FIA Prize Giving Ceremony - or back away completely.
What's the latest in F1 and will Merc appeal?
The aftermath to the Abu Dhabi GP decider has been understandably turbulent and contrasting, with Verstappen celebrating and conducting media calls about a well-deserved first crown, while the circumstances which led to him achieving that on Sunday continue to be questioned.
The FIA, F1's governing body, and Race Director Michael Masi have particularly come under increased scrutiny following the handling of the final laps and the rules, with the decision to run a final lap after the Safety Car - and allowing five cars to unlap themselves - ultimately having a huge say on the championship.
Given the seemingly loose application of what are complicated regulations, some may say the season ended with an entertainment angle in mind rather than a sporting one. From F1's side, they insist they did not influence the FIA and are passengers once the race starts, with the FIA and Race Director then making the decisions.
Masi, who like Mercedes has not commented publicly since the race, has made calls this year which have seen both drivers and teams in the title race blast a lack of consistency, but undoubtedly did what he felt was right in the dramatic and unique circumstances, which was seemingly for the most remarkable championship not to be ended under the Safety Car. "It's called motor racing," he said to Wolff on team radio after the race.
Along with criticism for the Australian, who replaced Charlie Whiting following his passing on the eve of the 2019 season, there has been empathy - insisting he needs more help, much like Whiting received when he was in charge.
There may well be changes when it comes to that over the winter break.
What has to be sorted sooner, though, is Mercedes' appeal, with the Silver Arrows already halfway through their 96-hour window to appeal after their initial post-race protests were dismissed.
But, needing to overturn the stewards' verdicts, the result of the race and subsequently the championship, it is an uphill battle.
"It sounds like Mercedes will probably back off from another appeal," said Sky Sports F1 commentator David Croft. "They don't want to look like bad losers, they have a championship to celebrate, they are constructors' champions for a record-breaking eighth time.
"They don't want to drag this on and damage the reputation of the sport, they just wanted to give the man they think should be champion, the best chance of being champion. They felt robbed by what happened."
Hamilton set to be knighted
And that's not all for a rather hectic week in F1 as Hamilton, who has been silent on the F1 finale since Sunday, is due to receive his knighthood on Wednesday
Hamilton, 36, is due to attend an investiture at Windsor Castle to be honoured for services to motorsports.
He was given his knighthood in the New Year Honours list in 2020 following pressure on Prime Minister Boris Johnson to approve the accolade.