Red Bull's Verstappen was 104 points behind then-leader Oscar Piastri at that point but has since overtaken the Australian by four points and is now chasing the McLaren driver's teammate, Lando Norris, in an astonishing comeback.
"No one anticipated Max Verstappen’s comeback," said William Hill spokesperson Lee Phelps in a press release.
"We could be heading to the pit lane should he manage to claw back the 12-point deficit on Sunday, as he’s by far our worst result in the outright market."
The bookmaker said Britain's Norris remained 1/3 (1.33) title favourite but most of the bets were now for his Dutch rival at 5/2 (3.50), with the two championship frontrunners accounting for 74% of all stakes. Piastri was priced at 12/1 (13.00).
Ladbrokes offered 1/4 (1.25) on Norris for the title, with Verstappen 3/1 (4.00) and Piastri also at 12/1 (13.00).
All three title contenders have won seven times this season. Norris won in Abu Dhabi last year after four years of Verstappen dominance.