Lewis Hamilton led a Mercedes one-two in Thursday’s practice at the season-opening Bahrain Grand Prix. Hamilton was 0.206 seconds quicker than team-mate George Russell with Aston Martin’s Fernando Alonso just 0.08secs further adrift.
Pre-season favourite Max Verstappen was down in sixth, 0.477secs off the pace.
However, the three-time world champion appeared to be the fastest as expected when the teams switched to race-simulation runs later in the session.
The teams did not run this practice session in the same manner as usual, making it even harder to read from the outside than normal.
After a complaint against Horner by a female colleague was dismissed by Red Bull on Wednesday, Mercedes and McLaren bosses Toto Wolff and Zak Brown have called for more transparency on the matter.
Behind Alonso, Ferrari’s Carlos Sainz was fourth quickest ahead of McLaren’s Oscar Piastri.
Haas driver Nico Hulkenberg was seventh, with Aston Martin’s Lance Stroll, Ferrari’s Charles Leclerc and Red Bull’s Sergio Perez completing the top 10.
The season starts with the controversy over Red Bull team principal Christian Horner still overshadowing the sport.
