Rohan Bopanna and his Pakistani partner Aisam-ul-haq Qureshi eked out a hard earned win over Michael Mertinak of Slovakia and Dick Norman of Belgium to book a place in the quarter-finals of the Sony Ericsson Open here.

The seventh-seed Indo-Pak pair defeated their unseeded rivals 7-6(4) 3-6 10-8 in the second round of the hard court event.