Championship leader Lewis Hamilton set the pace in a rain-hit final practice for the Formula 1 United States Grand Prix.

Heavy rain lashed Austin on Saturday casting doubt as to whether the session at the Circuit of The Americas would run on schedule. But after sending the safety car out to assess conditions, officials deemed the track clear for use and practice began on time.

With second practice on Friday canceled because of bad weather, there was plenty of running in the opening half off the session before the rain intensified. With rivers running across the track and puddles forming in places, the teams were informed by race control that intermediates were could not be used.

Nico Rosberg was among the first drivers to get caught out by the conditions, spinning at Turn 3 and tapping the barrier, which broke his front wing. His Mercedes teammate Hamilton also had a moment, catching the rear end as it stepped out at Turn 13 before continuing. However, the reigning world champion managed to get a flying lap in shortly before conditions started to worsen, moving himself to the top of the order.

Sebastian Vettel had a messy session, spinning first at Turn 19 and then Turn 9 and then complaining about aquaplaning as conditions worsened in the final half of the session. The Ferrari driver still managed to set the second-fastest time of the session, though, ahead of Nico Hulkenberg, Valtteri Bottas and Carlos Sainz Jr.

There were no improvements in the final 20 minutes, but several drivers headed out on track to perform practice starts, particularly as there’s a chance the start of Sunday’s race could be wet. Daniil Kvyat was sixth with Kimi Raikkonen, Daniel Ricciardo, Nico Rosberg and Felipe Massa completing the top 10.

Should qualifying not be able to take place at any point, the regulations suggest the grid will take the order in which they were classified in final practice.

Rain is expected to continue throughout Saturday, but even if qualifying is unable to be completed as scheduled, it could run on Sunday ahead of the race, as was the case for the Australian Grand Prix in 2013. However, COTA said in a statement that it expects the afternoon schedule to go ahead as planned:

“We encourage fans to start making their way out to the track. Be advised that further rain and wind is expected throughout the day, however we anticipate the afternoon activities to be on schedule. This is of course subject to change depending on weather conditions. Please check www.circuitoftheamericas.com for your parking and shuttle options.”

FP3 TIMES