Sainz and Charles Leclerc had locked out the top two positions following the opening foray of laps, with the two having saved a set of soft tyres each from Q2 to use at the start of the final shootout to throw down the gauntlet to Ferrari's competitors.
The Spaniard, who had set the earlier benchmark with a 1m31.170s to sit a quarter of a second clear of Leclerc, managed to better his time with a 1m30.984s to stake his claim for a second pole on the bounce after securing Saturday's spoils at Monza.
