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

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.

They will lock horn with giant-killers Oliver Marach [ Images ] of Austria and Serbia's Janko Tipsarevic [ Images ], who shocked top seeds and local favourites Bob and Mike Bryan [ Images ] 7-5, 6-4 in their pre-quarterfinal round.

The Indian pair of Leander Paes [ Images ] and Mahesh Bhupathi [ Images ], seeded third, is up against Spanish pair of Marc Lopez and David Marrero in their second round.

Somdev Devvarman [ Images ] had lost to David Ferrer to bow out of the men's singles event earlier.

Sania Mirza [ Images ] had lost to Maria Kirilenko in the women's singles event, being played simultaneously.