Lewis Hamilton set the pace in opening practice for the Brazilian Grand Prix, the Briton outpacing his closest rival by over half a second.
Hamilton posted a best time of 1:13.543 as he emerged as the only driver to lap the Interlagos circuit in the 1:13s range in the 90 minutes of running.
Mercedes teammate Nico Rosberg finished second, 0.519s behind the world champion, with Sebastian Vettel a close third in the quickest Ferrari.
Red Bull's Daniel Ricciardo was fourth ahead of Vettel's teammate Kimi Raikkonen, who was a full second slower than Hamilton.
Daniil Kvyat wound up sixth in the second Red Bull, with Williams' Valtteri Bottas in seventh ahead of Max Verstappen in the Toro Rosso.
Force India's Nico Hulkenberg and Pastor Maldonado in the Lotus completed the top 10.
Verstappen was the first man to get his name in the timesheets after the 10-minute mark, the Dutchman joined by Toro Rosso teammate Carlos Sainz moments later.
Rosberg went quickest 15 minutes in, posting the first time in the 1:15s, before Verstappen triggered a yellow-flag period as he spun at Turn 3.
Although Rosberg improved his best, Hamilton hit the front just seconds later with a 1:15.102, just 0.022 seconds quicker than his teammate.
The Briton set a new benchmark by diving into the 1:14s, increasing the gap to Rosberg to nearly three tenths before the German improved and got to within less than half a tenth.
First Verstappen and later Raikkonen went quicker to join the Mercedes duo as the only men in the 1:14s, with Vettel the first driver in the 1:15s.
Vettel jumped to P1 with 36 minutes to go, the Ferrari driver posting a 1:14.233 lap, but he did not stay there for long, as Rosberg went even quicker.
But with 30 minutes left, Hamilton regained the top spot with the first lap under 74 seconds, the Briton's 1:13.543 quickest by over half a second at that point.
Raikkonen's session was came close to ending early when he lost control of his car under braking at Turn 3, the Finn spinning intro the gravel but somehow managing to return to the pits, although he would not go out again.
All the laps in the session were completed with Pirelli's medium tyres.
|4||Daniel Ricciardo||Red Bull Racing||1:14.449||+0.906||27|
|6||Daniil Kvyat||Red Bull Racing||1:14.696||+1.153||25|
|8||Max Verstappen||Toro Rosso||1:14.960||+1.417||38|
|9||Nico Hulkenberg||Force India||1:15.174||+1.631||33|
|10||Pastor Maldonado||Lotus F1 Team||1:15.192||+1.649||31|
|11||Carlos Sainz Jr.||Toro Rosso||1:15.314||+1.771||38|
|12||Jolyon Palmer||Lotus F1 Team||1:15.352||+1.809||33|
|15||Sergio Perez||Force India||1:15.408||+1.865||32|