Mercedes have struggled to get on top of the new regulations
Twenty-four hours after a missile strike on a nearby oil refinery, the drivers were back on track for the concluding action ahead of qualifying on Saturday evening.
Hamilton and his fellow drivers were understood to have signalled their intention not to take part in Sunday’s race following the attack just 12 miles east of the Jeddah street circuit.
But after seeking assurances from Saudi officials, F1 bosses declared the second round of the new season “secure”, and it was Leclerc who led the way.
Leclerc, who won last weekend’s opening round in Bahrain, snatched the fastest time away from Max Verstappen in the final seconds.
Verstappen, denied second place in Bahrain following a late fuel failure, finished just 0.033 seconds behind Leclerc, and ahead of Red Bull team-mate Sergio Perez.
Mercedes have struggled to get on top of the new regulations and Hamilton finished a concerning 0.972 seconds off the pace, with team-mate George Russell even further back in 14th. British driver Lando Norris was only 19th for McLaren.
Qualifying takes place at 8pm local time (5pm UK).