Lewis Hamilton could clinch a fifth Formula One world championship at the United States Grand Prix and made the perfect start to the weekend by topping practice twice on a soaking Friday.
A wet track made early running slow but when Hamilton eventually emerged in his Mercedes he posted an unmatchable one minute and 47.502 seconds on a drying 5.5km Circuit of the Americas in the first session.
The second session was not a complete washout but steady, heavy rain meant there was little action.
Pierre Gasly of Toro Rosso looked set for the honour before Hamilton pipped him late on with 1:48.716 as some, though not all, cars took the track in the dying minutes.
Hamilton’s teammate Valtteri Bottas was second in the first outing but a huge 1.3 seconds down, while the Red Bull duo of Max Verstappen and Australia’s Daniel Ricciardo were ahead of Ferrari duo Sebastian Vettel and Kimi Raikkonen.
Vettel has seen ambitions for his own fifth title fade in recent weeks as he trails Hamilton by 67 points with just four races remaining, including Sunday.
Hamilton can confirm the championship by earning eight points more than Vettel and will feel confident at a track he’s dominated since it joined the F1 calendar in 2012.
The Briton has won five of six races at the venue in Austin, Texas.
Final practice is before qualifying on Saturday, with further rain possible in Texas during the sessions.