Toro Rosso's Max Verstappen, who was not even born last time Formula 1 raced in Mexico, set the pace in first practice as the sport returned to the country after a 23-year absence on Friday.
The 18-year-old Dutch driver, whose father Jos made his F1 debut two years after the last grand prix in Mexico City in 1992, lapped the Hermanos Rodriguez circuit in a best time of one minute 25.990 seconds. He appeared to cut a corner on the Esses sequence in doing so, however.
Red Bull's Russian Daniil Kvyat, also born two years after Britain's Nigel Mansell won that 1992 race, was second fastest 0.305 behind in a Renault-powered one-two at the top of the timesheets.
Britain's Lewis Hamilton, who took his third world championship last Sunday in Texas, was only 11th fastest and told to cool his brakes.
His Mercedes team mate Nico Rosberg, who is fighting Ferrari's Sebastian Vettel for second place overall with three races remaining, was sixth despite his car's rear brakes catching fire. The German headed back to the pits with flaming wheels but returned shortly before the end of the session.
Ferrari's Kimi Raikkonen and Vettel were third and fourth fastest. The high-altitude circuit, much revamped from the old one with the daunting Peraltada curve now cut in half, has one of the longest straights on the calendar and Friday's start to practice was in damp conditions.
"It's so slippery everywhere, it's like there's oil," commented Verstappen over the radio.
Spectators queued outside from early on, amid a heavy police presence and the usual traffic gridlock, to get a glimpse of the cars and home favourite Sergio Perez.
Mexico's only current Formula 1 driver, who is likely to be joined on the grid by Esteban Gutierrez next season, was ninth fastest.
[highlight ]Mexican Grand Prix, Hermano Rodriguez Circuit - Free Practice 1[/highlight]
| Pos. | No. | Driver | Team | Time | Gap | Laps |
| 1 | 33 | Max Verstappen | Toro Rosso | 1:25.990 | | 38 |
| 2 | 26 | Daniil Kvyat | Red Bull Racing | 1:26.295 | +0.305s | 27 |
| 3 | 7 | Kimi Räikkönen | Ferrari | 1:26.295 | +0.305s | 36 |
| 4 | 5 | Sebastian Vettel | Ferrari | 1:26.886 | +0.896s | 31 |
| 5 | 3 | Daniel Ricciardo | Red Bull Racing | 1:27.185 | +1.195s | 28 |
| 6 | 6 | Nico Rosberg | Mercedes | 1:27.196 | +1.206s | 19 |
| 7 | 77 | Valtteri Bottas | Williams | 1:27.303 | +1.313s | 26 |
| 8 | 55 | Carlos Sainz | Toro Rosso | 1:27.410 | +1.420s | 37 |
| 9 | 11 | Sergio Perez | Force India | 1:27.581 | +1.591s | 19 |
| 10 | 19 | Felipe Massa | Williams | 1:27.695 | +1.705s | 24 |
| 11 | 44 | Lewis Hamilton | Mercedes | 1:27.723 | +1.733s | 27 |
| 12 | 9 | Marcus Ericsson | Sauber | 1:28.498 | +2.508s | 27 |
| 13 | 13 | Pastor Maldonado | Lotus | 1:28.559 | +2.569s | 30 |
| 14 | 12 | Felipe Nasr | Sauber | 1:28.579 | +2.589s | 25 |
| 15 | 30 | Jolyon Palmer | Lotus | 1:28.711 | +2.721s | 24 |
| 16 | 27 | Nico Hulkenberg | Force India | 1:29.099 | +3.109s | 17 |
| 17 | 14 | Fernando Alonso | McLaren | 1:30.072 | +4.082s | 17 |
| 18 | 53 | Alexander Rossi | Marussia | 1:30.619 | +4.629s | 23 |
| 19 | 22 | Jenson Button | McLaren | 1:32.091 | +6.101s | 9 |
| 20 | 28 | Will Stevens | Marussia | 1:32.866 | +6.876s | 11 |