Max Verstappen made an impressive start to Formula 1's return to Sepang International Circuit, setting the fastest time of 1:37.520 in first practice. The Red Bull driver, who won the last race at the Malaysian venue in 2017, was three-tenths of a second quicker than second-placed George Russell.
Russell finished as Verstappen's closest challenger in a Mercedes featuring a major aerodynamic upgrade package. The Silver Arrows introduced their first significant car update since the Canadian Grand Prix in May, including a new floor, rear suspension and rear corner modifications.
Championship leader Kimi Antonelli struggled in the session, finishing fifth and a full second off Verstappen's pace. The Italian was 0.6 seconds slower than teammate Russell alone, adding pressure after Russell's recent victory in Baku had cut Antonelli's title lead to 66 points.
Ferrari faced difficulties with both Charles Leclerc and Lewis Hamilton finishing over 0.8 seconds behind Verstappen in fourth and sixth respectively. McLaren had an even more challenging session, with Oscar Piastri and Lando Norris completing the top 12 as the team tested different rear wing specifications.
The hot and humid Malaysian conditions created immediate tire degradation concerns on the dusty track surface. Teams struggled with setup in the extreme heat, with Mercedes appearing as an outlier in terms of higher tire wear during long runs on soft compounds.