The defending champion could surrender his title this weekend with a 10th-place finish or worse should Mercedes teammate Nico Rosberg triumph tomorrow.
Rosberg, who won the Mexican Grand Prix last year, had been off the pace during practice, but saved his best lap until last to join Hamilton on the front row of the grid for Sunday’s race.
The German currently sits 26 points ahead of Hamilton in the standings heading into the final three races, and could edge closer to his maiden crown even if he finishes second to Hamilton in Mexico.
His final lap saw him leapfrog Red Bull duo Max Verstappen and Daniel Ricciardo on the grid, with those two qualifying third and fourth fastest respectively.
Nico Hulkenberg of Force India will begin the race in fifth place, just ahead of Ferrari pair Kimi Raikkonen and Sebastian Vettel in sixth and seventh respectively.