PHOTO: FILE
The duo defeated Serbian pair of Dusan Lajovic and Viktor Troicki 6-2, 6-3 on Court 16 of the USTA Billie Jean King National Tennis Center in New York City.
Aisam and Muller outplayed Lajovic and Troicki's in just 57 minutes with the help of four aces and a total of 59 points won compared to the Serbians' 34.
Aisam and Muller also broke their opponents' serve thrice during the match supported with four winners.
They will face the winner of the match between 16th seeds Feliciano Lopez and Max Mirnyi and American pair of Eric Butorac and Scott Lipsky.
Aisam and Muller are unseeded in the tournament.
The 35-year-old Aisam is the only Pakistani to reach the finals of a Grand Slam. He was the US Open men's doubles and mixed doubles finalist in 2010.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ