Mirza and Bhupathi beat Nathalie Dechy of France and Andy Ram of Israel 6-3, 6-1 at Rod Laver Arena.
Bhupathi and Mark Knowles of the Bahamas lost the men's doubles final Saturday to American twins Bob and Mike Bryan.
Seven of the 34-year-old Bhupathi's majors have come in mixed doubles. He won a mixed title at the Australian Open in 2006 with Martina Hingis.
Bhupathi and 22-year-old Mirza broke Dechy's serve in the opening set, then broke their opponents twice in the second. Bhupathi was dominant at the net throughout the match.
Mirza, Bhupathi win mixed doubles title
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