The Canadian, who is fighting for a new contract to stay on the grid with Team Grove, surprisingly rose to the top in the dying moments of a slippery FP3 to beat second practice leader Leclerc.
Alex Albon, who took the flag moments before teammate Williams, secured third place ahead of former Red Bull teammate and defending champion Max Verstappen.
A downpour in the hour before FP3, which helped flood the paddock and caused a few engines to leak, created a national start to Saturday’s one-hour session.
Leclerc was the first car out after three minutes, followed shortly by team-mate Sainz, then the two McLarens, the Alfa Romeo of Zhou Guanyu, Lance Stroll and Mick Schumacher joined the action.
The rain tire was the choice of the peloton, with Leclerc taking the blue-walled rubber to 1m46.044s initially before Carlos Sainz found half a second to sit tentatively at the front of the pack.
Then two-time champion Fernando Alonso ventured onto intermediates, requiring numerous corrections throughout the lap and he was eventually 5.8 seconds off the pace as the crossover point had not yet arrived.
The integral rains continued to be the optimal tire for the conditions, as Leclerc needed just 10 minutes to post his 1m43.364s effort that would take him to the top of the standings for most of the session.
This gave him a cushion of 1.25s over Sainz before heavier rain arrived – with neither Red Bull or Mercedes car leaving the garage.
With Leclerc and Sebastian Vettel off the track at Turn 7, the Ferrari benchmark remained, although Alonso was able to at least close within 2.4 seconds to move into third place ahead of Daniel Ricciardo.
Stroll would topple Alonso before a series of errors at Turn 4 – Zhou, Pierre Gasly, Latifi and Albon fighting understeer and oversteer to demand clearance on the outside of the left corner at medium speed.
With conditions deteriorating, Lewis Hamilton and Leclerc completely evacuated the cockpit to leave only Mick Schumacher on track after 22 minutes.
Six minutes later, the track was relatively busy as the standing water began to clear – this allowed the Haas cars to climb to 3-4 and the forecast said there would be no more rain as visibility was improving.
That wouldn’t stop Pierre Gasly from pulling out a yellow flag shortly after when he cut the inside kerb at Turn 7 to turn, which preceded George Russell who went straight on at Turn 12.
It came as Mercedes struggled to generate tire temperatures at the rear axle, prompting a nod from Lewis Hamilton.
As Alonso moved back to second, posting a 1m43.570s, as he persisted with the intermediates, Aston Martin driver Vettel then signaled a red flag with nine minutes to go.
The AMR22 broke away from the retired four-time world champion on the left-hander of Turn 10, introducing him to a career through gravel and the biff side into the barrier.
The session would resume six minutes later, with Verstappen finally completing a representative lap as the checkered flag came out to move fastest, with the RB18 clocking a time of 1m43.205s.
He was then immediately knocked down the line by Leclerc, the Ferrari driver – who moments before took a 360 degree spin from Turn 3 – improving to 1m42.141s.
With Albon in what would be third in the final moment, all eyes were on Latifi in the Williams.
He had held the best time of all in the first sector of the updated FW44.
And as the last driver to cross the line, the Canadian had assembled a sequence of micro purple sectors to cross the line in 1m41.480s to find 0.6s on Leclerc.
This happened despite having to round an AlphaTauri at turn 1 and numerous corrections.
Verstappen, as a result, would be relegated to fourth place ahead of Russell and Alonso.
Meanwhile, FP1 topper Sainz would be relegated to seventh on Norris and Vettel’s final attempt.
Kevin Magnussen completed the top 10 ahead of Hamilton, Schumacher and Esteban Ocon.
Ricciardo and Stroll led Zhou, while Tsunoda finished a messy session for AlphaTauri in 17th over Valtteri Bottas, Gasly and Sergio Perez – Red Bull completed the fewest laps with just 21 combined.
#Hungarian #Latifi #tops #wet #test