BARCELONA, Spain – Valtteri Bottas put down the fastest lap of the day for Mercedes during the opening day of practice for the Spanish Grand Prix at Circuit de Barcelona-Catalunya Friday.

Bottas led the way thanks to his time from the opening practice, a 1:16.785. He fell to second fastest behind Hamilton during the second practice, but Hamilton wasn’t able to top Bottas’ quick lap from the opening session and settled for second overall.

Bottas said the high temperatures Friday made practice even more of a challenge than usual.

“It’s definitely been quite tough out there today. I don’t think I’ve ever been to Spain when it’s been this hot,” Bottas said. “The weather is beautiful, but it’s tricky for the car and very tough on the tires as well. It’s also been quite windy and that can make it difficult out there, but it’s a good challenge. It’s been a positive day, particularly the second session which went better for me. We didn’t see any blistering, the tyres felt OK and the long runs didn’t look too bad, but we also didn’t see any blistering last Friday, so we’ll have to remain careful. We’ll debrief this evening and see where we stand and what we can do to improve. The Red Bulls look very close to us on the long runs, so we can expect another close race here.”

Red Bull’s Max Verstappen, who won the 70th Anniversary Grand Prix last weekend at Silverstone, was third fastest on the day. Daniel Ricciardo was fourth overall on the combined timesheets.

The Ferrari entries of Charles Leclerc and Sebastian Vettel were next ahead of the surprisingly fast Haas F1 entry of Romain Grosjean. Grosjean was sixth in the first practice and backed up his speed by going fifth fastest in the second session.