Top seed Sania Mirza inched closer to her second consecutive ITF singles title, advancing to the semi-finals of the US $75,000 tournament in Vancouver but not before facing a spirited fight from unseeded Rebecca Marino.

Sania had to dig deep into her reserves to edge past the local favourite 7-6(2), 6-7(3) 6-4 in the quarter-final of the hard-court tournament.

The Indian will now fight it out with another unseeded local Sharon Fichman for a place in the final.

Fichman beat compatriot Marie-Eve Pelletier 6-2, 6-1 in the other quarter-final.

Sania had won the Lexington Challenger tournament recently.