Briton Lando Norris was quickest in his McLaren in first practice on Friday for Sunday's Spanish Formula One Grand Prix in Barcelona.
Norris, second in Canada last time out and winner in Miami this season, set a best lap of 1 minute 14.228 seconds in sunny conditions.
World champion Max Verstappen, who won in Canada in very different wet weather, was second fastest in his Red Bull. The standings leader was just 0.024 seconds behind Norris.
Third fastest was Ferrari's Carlos Sainz.
Fellow Spaniard Fernando Alonso prompted a red flag in his Aston Martin while Red Bull's Sergio Perez, due to serve a three-place grid penalty in Saturday's qualifying, reported issues with his throttle.
Ferrari's Charles Leclerc also complained: “The car is horrendous for now.”
A second practice session follows later on Friday.
