Paes-Dlouhy made a spirited comeback after going down in the first set but lost it in the closely fought super tie-breaker.

They squandered three breakpoints in the first set to hand the lead to their Italian-Croatian rivals but pulled up their socks and outplayed them in the second to draw parity.

However, Bolelli and big serving Karlovic edged past their fancied rivals in the deciding tie-breaker to book a quarterfinal berth for themselves.

Mahesh Bhupathi and Prakash Amritraj are also in the fray with their respective partners. Bhupathi and Mark Knowles of Bahama, seeded second, will play their opener against UAE's wild card entrants Hamoud Abbas and Mahmoud-Naden Al Baloushi.