What you need to know:
Lewis Hamilton's quest to make Formula One history at the Abu Dhabi Grand Prix began brightly with the Mercedes driver topping the timesheets after Friday's opening practice.
Hamilton, chasing an unprecedented eighth world title, goes into Sunday's season-closing race level on points with Max Verstappen.
And it was the Dutch title contender who was quickest out of the blocks at the Yas Marina circuit, taking the honours in the morning session.
Hamilton, placed third, turned the tables under floodlights in second practice with a 1min 23.691 lap to get his weekend off to an encouraging start.
"It doesn't feel too bad," said the 36-year-old Briton.
"It started off good but got a bit worse in P1, then started off better in the second session with some changes we made.
"Now we just have to crank through the data and try to figure out how we can improve, where we home in. The target is always moving, but yes. Otherwise, I feel good."
Alpine's Esteban Ocon led the chasing pack, 0.343sec adrift, followed by Valtteri Bottas on his last run out for Mercedes before moving to Alfa Romeo in 2022.
Verstappen, who won at the circuit last year to end six years of domination by Mercedes, was placed fourth, at 0.641sec.
The Abu Dhabi track has undergone a major revamp since last year to improve overtaking opportunities, and on the evidence of opening practice it appears to suit Mercedes better than Red Bull.
"We're still learning and understanding a few things," reported the 24-year-old Verstappen.
Red Bull team principal Christian Horner said the boffins will be hard at work trying to find more speed to make up the difference in pace with Mercedes.
"We've still got 24 hours or 23 hours (before qualifying) to try and find a better set-up and a bit more pace."
Hamilton approaches Sunday's closing chapter of a 2021 season that will live long in the memory on a four-timer after wins in Brazil, Qatar and Saudi Arabia.
His late season surge sees the pair neck and neck at the top of the drivers' standings - the last time that happened was in 1974.
The maths are simple -- whoever finishes with more points takes the title.
But Verstappen will prevail should they both end up all square -- (one finishes 9th, the other 10th with fastest lap) or fail to score any on the strength of winning nine races to Hamilton's eight.
Abu Dhabi is the 22nd and final port-of-call for a season that has seen sparks fly between Toto Wolff, Mercedes team principal, and Horner.
But the two team chiefs met and shook hands on Friday, both quick to play down fears the title could be decided by a crash, like at Silverstone with Verstappen retiring or Monza with both cars knocked out.
"Nobody approaches the race saying it's going to end in a crash," said Horner. "Our aim is to win on the track."
He added: "It's almost like Squid Game (the popular Netflix series), the fact that we've arrived here level."
"May the best man and the best team win," added Wolff, with Mercedes and Red Bull also fighting it out for the constructors championship.
Friday's action was red-flagged at the end when Kimi Raikkonen, who is retiring after this weekend, crashed at turn 14.
The 2007 world champion emerged unscathed from his smashed up Alfa Romeo.