What happened: Isack Hadjar endured a catastrophic run of mechanical issues during qualifying for the Singapore Grand Prix, leaving him stranded at the bottom of the grid. After a terminal power unit failure forced his retirement from the Sprint race, hurried engine repairs failed during Q1 before a secondary gearbox fault cost him all gears.

Why it matters: The cascade of failures leaves Red Bull facing drastically contrasting fortunes, with teammate Max Verstappen securing pole position. Breaking parc fermé to install a completely new power unit would incur further penalties but provide a functional car for Sunday's main event.

What to watch: Team principal Laurent Mekies must decide during the overnight debrief whether to break parc fermé regulations to install a fresh power unit.