Lewis Hamilton trailed Ferrari team-mate Charles Leclerc by more than half-a-second in first practice for the Hungarian Grand Prix.
Hamilton has a record eight wins at the Hungaroring but he complained about the handling of his Ferrari in the opening running as Leclerc led the way.
Leclerc finished 0.484 seconds clear of Red Bull’s Max Verstappen with Hamilton third, 0.543 sec adrift.
Verstappen’s team-mate Isack Hadjar took fourth spot, a place ahead of George Russell who was nearly one second off the pace.
Kimi Antonelli did not take part in the opening running with rookie drivers from five of the grid’s 11 teams in action.
Antonelli, who holds a 45-point lead at the world championship summit, will return for second practice later on Friday.
Hamilton heads into the concluding round prior to the sport’s three-week summer shutdown as the driver nearest to Antonelli in the standings.
The twisty venue here a dozen miles outside of Budapest is expected to play to Ferrari’s strengths but the setup of Hamilton’s machine was not all to his likening.
“Something is wrong with the upshifts, and downshifts,” he said on the radio. “Like downgraded upshifts and downshifts all the time.”
Leclerc might have set the quickest lap, but it was not all plane sailing for the Monegasque after he crawled back to the pit lane with seven minutes remaining.
After complaining that “something broke” on his Ferrari, Leclerc departed his cockpit with his mechanics wheeling his stricken car back to the garage.
The running was briefly red-flagged after Lance Stroll’s rear-left suspension failed on his heavily revised Aston Martin.
The British team have brought a total of 16 upgraded components here in the hope of salvaging what has so far been a dismal season.
Stroll finished last but one after the mechanical failure contributed to his spin at turn three. However, Fernando Alonso was able to take 13th, a somewhat encouraging, if not spectacular, 2.4 sec behind Leclerc.
The second session begins at 17:00 local time (16:00) BST.