Championship leader Hamilton’s closest rival, Max Verstappen, had been second fastest in the morning for Red Bull but dropped to ninth, 0.615 off the pace, in the afternoon at the Circuit de Catalunya.
Bottas had set the morning pace with a lap of one minute 18.504 seconds, 0.033 faster than Verstappen, but Hamilton put in a 1:18.170 effort on soft tyres after lunch when the conditions were warmer. That was 0.139 quicker than Bottas’s best effort in the session. Ferrari’s Charles Leclerc ended the second session third fastest, with Alpine pairing Esteban Ocon and Fernando Alonso fourth and fifth.
Hamilton is eight points clear of Verstappen after winning two of the three races so far. The Briton has won in Spain for the past four years and five times in total.
“Less than a tenth between ourselves and Mercedes, at a track like this that’s been a stronghold for them for the last seven years or so, that’s encouraging,” Red Bull principal Christian Horner told Sky Sports television after first practice. “Mercedes have been truly dominant here for the last few years. I think if we can get close to them here that’s a really encouraging sign.”
Bottas, who dismissed questions on Thursday about his future and the possibility he could be replaced mid-season, will be chasing his second successive pole position on Saturday. Verstappen’s Mexican team-mate Sergio Perez was only ninth and 10th in the two sessions.
Sunday’s race will be Verstappen’s 100th start for Red Bull and marks a return to the circuit where the Dutch driver became the sport’s youngest ever winner on his team debut as an 18-year-old in 2016. The 23-year-old has fallen foul of track limits in recent races, having times deleted for going too far wide, but Horner doubted that would be a big issue this weekend.
“I certainly hope it won’t, it’s not that type of a circuit,” he said, adding that there would be more discussion about the rules between team principals on Saturday.
The opening session was halted with 15 minutes remaining when Alfa Romeo reserve Robert Kubica, making his first Friday appearance of the season, went off into the gravel at the revised turn 10. Haas’s Nikita Mazepin also spun, something that has become a regular occurrence for the Russian rookie. The virtual safety car was deployed in the afternoon when some bodywork came off Carlos Sainz’s Ferrari and had to be retrieved.