Mortara got loose into the first corner and looked down and out by the end of the first sector - de Vries going three-tenths faster off the bat.
But Mortara regrouped and reeled off two rapid final sectors, beating de Vries in both, but the Mercedes driver was only just able to absorb his rival's late charge and held pole by the merest of margins - albeit was left "disappointed" by his pole-winning lap.
