Francesco Bagnaia and Jorge Martin will take their MotoGP title duel to the Malaysian Grand Prix at Sepang on Sunday, with the championship too close to call with three races left.
Italy's Bagnaia tops the standings on 389 points, just ahead of Martin on 376, with the Spaniard having closed the gap last time out with a thrilling victory in Thailand.
Marco Bezzecchi is mathematically still alive in the world championship fight in third, on 310 points, but realistically it is a straight shootout between the top two.
A maximum of 111 points are up for grabs over the next three weekends, including the sprint races.
Ducati's Bagnaia is the reigning title-holder but Martin – who is chasing his first world crown – has gradually reeled in his rival over the second half of the 20-event season.
The Pramac rider ramped up the pressure by winning his seventh sprint race of the campaign in Thailand and followed that up by sealing a nail-biting fourth grand prix victory of 2023.
The 25-year-old Martin admitted to sleepless nights as a roller-coaster season goes to the wire.
"I can admit that I already feel the pressure," he told reporters after his triumph at Buriram.
"I have not slept. I need four or five days of not thinking about motorcycles.
"I am mentally destroyed."
The 26-year-old Bagnaia also cut an emotional figure in Thailand and was especially disappointed to finish seventh in the sprint race.
The Italian crossed the line third, behind Brad Binder, in the grand prix but was awarded second after the South African was penalised one place for exceeding track limits on the final lap.
"I'm just a bit angry I lost too many points in the sprint race and I think we need to improve a bit," said Bagnaia, who won in Malaysia last year after Martin crashed out.
The Italian's experience of winning the world title last year could be an advantage as they approach the business end of the campaign.
"In terms of pressure, last year was higher," he told motogp.com.
"It was more intense and I felt more the weight on my shoulders.
"This year is different. I feel a lot of pressure – the same – but in a more motivational way."
Like in Thailand a fortnight ago, the steamy weather will again be a factor in Malaysia.
Temperatures all week are forecast to push 33 degrees Celsius (91 Fahrenheit) coupled with punishing humidity and an ever-present threat of tropical thunderstorms.
The Sepang International Circuit, near Kuala Lumpur, used to host Formula One and provides plenty of opportunities for high-speed racing and overtaking.
It is a wide track with two long straights and one of the longest laps in MotoGP.
The action starts on Friday with practice, followed by more practice, qualifying and a 10-lap sprint race on Saturday.
The 20-lap grand prix is on Sunday.
No matter what happens in Malaysia, the title fight will remain alive going into the penultimate race in Qatar followed by the season-ender in Valencia at the end of November.