The Ferrari driver and pre-event championship leader returned to his FP1 form by also racing uphill in the second of Friday’s one-hour practice sessions in Barcelona.
Leclerc ran flawlessly in his qualifying race on soft Pirelli C3 tires at 1m19.670s.
That found 0.16s above his FP1 benchmark effort, closer to 0.6s of Hamilton’s pre-season test time at the venue in late February on the fastest C5 compound rubber.
This gave Leclerc a 0.117 second lead over Russell, the Mercedes driver who set the pace in EP2 last time out for the inaugural Miami Grand Prix.
Hamilton was a late adopter of the soft tire and raced particularly well in the latter part of the second sector to clinch the third-fastest effort – albeit 0.09s behind his team-mate.
Meanwhile, before his home race, Carlos Sainz guided the second Ferrari F1-75 to fourth place ahead of defending champion Max Verstappen.
Alexander Albon, Mick Schumacher, Aston Martins and Esteban Ocon were the first drivers to hit the track in FP2 as the field initially stuck to medium and hard tyres.
Sergio Perez and Albon also had their first race of the weekend after missing FP1 as Formula 2 race winner Juri Vips (Red Bull) and Formula E champion Nyck de Vries (Williams) led their first weekend GP practice sessions.
Likewise, Zhou Guanyu returned to the cockpit of the Alfa Romeo after giving way to Robert Kubica during the first tests.
Verstappen had been the first driver to achieve a fairly representative lap time on medium rubber as he and Sainz fell below the 1m21s threshold ahead of Leclerc and the Mercedes.
But after just 11 minutes, the session was interrupted by a virtual safety car.
This intervention was necessary when the Alfa Romeo of Valtteri Bottas, sixth at the time, expired on the straight after the Finn had completed only three laps.
Valtteri Bottas, Alfa Romeo C42, parks with a technical problem
Photo by: Steven Tee / Motorsport Images
A puff of smoke from the rear was accompanied by the engine appearing to die out quickly as Bottas came to a stop on the edge of the track on the exit of Turn 1.
After the three-minute VSC, the other notable incidents hit Albon and Lando Norris as both exited the high-speed right-hander of Turn 9.
This allowed them to peek over the outside pavement, kick up some gravel, and send sparks flying.
Both drivers anticipated ground damage from their ground effect machines, but as Albon continued the session, Norris was forced back into the McLaren garage for the remainder of FP2 after completing just six laps.
Albon and Sainz also remain under investigation by stewards after a close call between the pair at Turn 2.
After 21 minutes the switch to soft tires and halo qualifying arrived with Vettel taking the lead in the heavily updated and controversial Aston Martin AMR22.
His 1m20.703s – then the fastest of 0.23s – was quickly dislodged by Perez, despite the Red Bull driver losing pace due to traffic in Turn 10.
Verstappen then buzzed the timing line with his 1m20.006s, finding a whopping 0.7s margin at the time.
He will remain the fastest driver in the first and the last sector but will drop back in the middle of the lap.
Then Sainz, Mercedes and Leclerc set the ultimate times to lead FP2.
It was less rosy for Leclerc in his last race on medium tyres, however, as he lost several tenths per lap to Verstappen as he complained about tire behavior and degradation.
Fernando Alonso guided his Alpine to sixth in front of his home crowd, while Perez and Vettel slipped to seventh and eighth ahead of Esteban Ocon and Mick Schumacher.
Pierre Gasly was the first driver to miss the top 10, the AlphaTauri ahead of the Haas of Kevin Magnussen and Lance Stroll.
Yuki Tsunoda finished 14th ahead of Daniel Ricciardo to end a trying afternoon for McLaren, while Bottas’ very early swim left him 16th ahead of teammate Zhou.
Norris completed the times behind both Williams, with Albon ahead of Nicholas Latifi.