Lewis Hamilton beat Max Verstappen to fastest time by 0.184 seconds in the second Formula 1 free practice session for the Singapore Grand Prix.
Hamilton hit the front for Mercedes during the early running when he was on medium-compound Pirellis, setting a best time of 1m39.991s.
Verstappen, on hards, was second quickest for Red Bull during this phase of the 90-minute session but seven-tenths slower than Hamilton.
As usual, the 20 cars then switched to soft rubber for their qualifying simulation runs.
Alex Albon, in the second Red Bull, was the first to hit the top of the timesheets on that rubber with a time of 1m39.943s, only to be relegated to second shortly afterwards by Verstappen.
Hamilton then took first place with a lap of 1m38.773s, which stood as the fastest of the session.
Both drivers attempted to improve but were unable to do so on subsequent attempts, with Verstappen making it clear over the radio that he felt he could do better as his best lap was "compromised" in the final sector.
The Ferrari drivers were frustrated by traffic early in their qualifying simulation runs, with Sebastian Vettel suggesting Kevin Magnussen was "sleeping" after the Haas driver got in his way.
But they eventually did complete push laps, with Leclerc, who lost most of practice one to a gearbox failure, was 0.111s quicker than Vettel initially before the four-time champion jumped to third and left his team-mate back in sixth.
Valtteri Bottas recovered from his practice one crash with fourth fastest time, but was 1.121s off his pacesetting team-mate.
He was just half-a-tenth faster than Albon, who ended the session in fourth place after a difficult session during which he had an early trip up the Turn 7 escape road at the end of the kinked back straight before crunching his front wing into the barriers at the Turn 10 left-hander.
McLaren driver Carlos Sainz Jr was seventh fastest and just 0.016s slower than Vettel - putting him almost two tenths clear of Renault driver Nico Hulkenberg in eighth.
Lando Norris took ninth for McLaren, lapping two tenths slower than Sainz, with Toro Rosso driver Pierre Gasly rounding out the top 10.
Daniil Kvyat, who had an early brush with the wall, was 11th fastest and within a tenth of team-mate Gasly - with Renault's Daniel Ricciardo 12th.
Racing Point's Sergio Perez was 13th, 2.10s off the pace, but angered Magnussen during the qualifying simulation runs when he drifted to his right while the Haas driver was attempting to pass him on that side. The stewards will investigate the incident after the session.
Alfa Romeo driver Antonio Giovinazzi was classified 14th ahead of Racing Point's Lance Stroll.
The pair set identical lap times - 1m41.128s - but Giovinazzi was placed ahead as he had set his time earlier in the session.
Kimi Raikkonen was 16th in the other Alfa Romeo, losing out to his team-mate in the first and third sectors of the lap.
Haas drivers Romain Grosjean and Magnussen were 17th and 19th respectively, putting them in among the Williams drivers.
George Russell was 18th having been as high as sixth thanks to being the first driver to complete a qualifying simulation lap, with Kubica last after lapping 0.732s off his team-mate.
Practice two times
|2||Max Verstappen||Red Bull/Honda||1m38.957s||0.184s||29|
|5||Alexander Albon||Red Bull/Honda||1m39.943s||1.170s||30|
|7||Carlos Sainz Jr.||McLaren/Renault||1m40.145s||1.372s||33|
|10||Pierre Gasly||Toro Rosso/Honda||1m40.637s||1.864s||32|
|11||Daniil Kvyat||Toro Rosso/Honda||1m40.713s||1.940s||32|
|13||Sergio Perez||Racing Point/Mercedes||1m40.875s||2.102s||29|
|14||Antonio Giovinazzi||Alfa Romeo/Ferrari||1m41.128s||2.355s||35|
|15||Lance Stroll||Racing Point/Mercedes||1m41.128s||2.355s||31|
|16||Kimi Raikkonen||Alfa Romeo/Ferrari||1m41.232s||2.459s||28|