It looked as if Mercedes was in excellent shape at early portion of the session, as Bottas and Hamilton both used medium tyres to lap quicker than the soft-tyred Ferraris initially.
Bottas directed the way in which on the 1m32.340s plus it required several tries before Vettel fractionally displaced him towards the top of the timesheet.
Ferrari afterward took a significant step forward, since Vettel broke into the 1m31s and Leclerc slotted in to instant on 1m31.884s, 0.137s down on his teammate.
When Mercedes finally bolted soft tyres onto its cars, Bottas leapt straight back to the top, even though a small second at Flip 10, setting a 1m31.328s best to stretch four-tenths clear of Ferrari.
Hamilton then piled into second spot, just under three tenths down Bottas, even though conducting wide at the final corner.
However, Ferrari made one final push, together with both cars carrying to the trail on soft tyres breaking and again in to the 1m30s.
Vettel moved briefly to the top with a 1m30.617so attempt, until Leclerc went faster still to maintain the top spot and earn an emphatic statement at the onset of a major weekend for the Scuderia.
Pierre Gasly endured a tricky start to the semester at the 2nd RedBull, whining it had been”super-oversteery” on the apex of corners on the challenging tyre and requesting the team to examine the engine shredding configurations.
He hooked a lap together on soft tyres that was less than two tenths down Verstappen.
The McLaren of Carlos Sainz, that has obtained a new Renault engine for this weekend after a fiery MGUK failure at the Australian Grand Prix, has been a remarkable seventh fastest, just 0.137s down Gasly.
Williams yet more brought up the back of the field, together with George Russell incurring car damage from a pitlane beginning and putting up with from spin.
He had been almost seven tenths down on the Racing Point-of Lance Stroll, who suffered their own spin exiting Turn 4 early and struck the interior obstacle.