Title favourite Lewis Hamilton finished second in final practice for the Mexican Grand Prix as Red Bull driver Max Verstappen soared to the top of order.
Hamilton will surpass Sir Jackie Stewart to become the first Briton to win the championship on more than three occasions if he finishes in the top five here at the Autodromo Hermanos Rodriguez in Mexico City tomorrow.
The 32-year-old Englishman - a winner of five of the last six grands prix - fell just short of ending the final practice session before qualifying with the fastest time.
Verstappen posted a best effort of one minute and 17.113 seconds - the quickest ever recorded here - to finish seven hundredths clear of Hamilton with Sebastian Vettel next up.
Vettel, who has been cast 66 points adrift of Hamilton, must finish either first or second tomorrow to stand any chance of taking the championship battle to the penultimate round of the season in Brazil in a fortnight's time.
Although Hamilton has been in scintillating form of late, it looks as though he will have his work cut out to seal the title in style.
The Briton has failed to finish either of the three practice sessions on top with Valtteri Bottas setting the pace in yesterday's opener, Daniel Ricciardo fastest in the afternoon running, and Verstappen quickest this morning.
The top five were separated by less than a quarter of a second with Bottas just 0.170 sec adrift of Verstappen in fourth and Ricciardo fifth in the order. Kimi Raikkonen finished sixth for Ferrari.
Elsewhere, Mexican home favourite Sergio Perez finished seventh ahead of his Force India team-mate Esteban Ocon. Carlos Sainz was ninth for Renault with his team-mate Nico Hulkenberg rounding out the top 10.
Third practice times:
1 Max Verstappen (Ned) Red Bull 1min 17.113secs
2 Lewis Hamilton (Gbr) Mercedes GP 1:17.188
3 Sebastian Vettel (Ger) Ferrari 1:17.230
4 Valtteri Bottas (Fin) Mercedes GP 1:17.283
5 Daniel Ricciardo (Aus) Red Bull 1:17.361
6 Kimi Raikkonen (Fin) Ferrari 1:17.517
7 Sergio Perez (Mex) Force India 1:18.040
8 Esteban Ocon (Fra) Force India 1:18.165
9 Carlos Sainz (Spa) Renault 1:18.208
10 Nico Hulkenberg (Ger) Renault 1:18.380
11 Brendon Hartley (Nzl) Scuderia Toro Rosso 1:18.602
12 Felipe Massa (Bra) Williams 1:18.690
13 Lance Stroll (Can) Williams 1:19.066
14 Kevin Magnussen (Den) Haas F1 1:19.205
15 Marcus Ericsson (Swe) Sauber-Ferrari 1:19.331
16 Fernando Alonso (Spa) McLaren 1:19.565
17 Romain Grosjean (Fra) Haas F1 1:19.586
18 Pascal Wehrlein (Ger) Sauber-Ferrari 1:19.826
19 Stoffel Vandoorne (Bel) McLaren 1:20.030
20 Pierre Gasly (Fra) Scuderia Toro Rosso No Time
Related links
Fast Results
Scores