Mattek-Sands and Mirza have been one of 2013's most prolific teams, collecting Premier-level titles in Brisbane and Dubai - the third and fourth of their partnership. They also were runners-up in Stuttgart.
"We've had a great year so far," Mattek-Sands said. "We're best friends and that helps a lot."
"We've been doing well this year," Mirza said. "What we haven't done yet is win a Grand Slam title, which is eventually our goal."
Seeded fifth this week, Mattek-Sands and Mirza took on Daniela Hantuchova and Anabel Medina Garrigues in the first round. In a rollercoaster first set, they were down a break at 4-3, 5-4 and 6-5 yet broke serve each time en route to a tie-break they won comfortably. After dropping the second set, Mattek-Sands and Mirza never trailed in the match tie-break and went on to a 76(3) 46 104 triumph.
"It was tough conditions at first, with swirling winds," Mattek-Sands said. "I think all of us are trying to figure it out. We were up against a very good team, so it's a good win for us and we're happy with it."
"We were all struggling with our rhythm in the beginning," Mirza said. "It was a good win, especially against such a good team in the first round."
The only other seeds in action, No.7 seeds Zhang Shuai and Zheng Jie, went down at the hands of Kristina Mladenovic and Galina Voskoboeva, 64 61. Mladenovic is fresh off a title in Oeiras alongside Chan Hao-Ching to put her in a tie for the WTA lead with three doubles titles so far this season.
In a noteworthy match involving unseeded duos, Svetlana Kuznetsova and Flavia Pennetta were 63 57 106 winners over Dominika Cibulkova and Liezel Huber despite letting a 5-3 second set lead slip away. Huber's partner in her 2009 Madrid championship run, Cara Black, was victorious in her opener with Marina Erakovic against Alizé Cornet and Francesca Schiavone.