Nestor and Mladenovic, who won the Wimbledon title last year, fended off all five break points and broke the Mirza-Tecau combination four times in the 58-minute match.
Kiki, she's the best mixed doubles player. She really helps me out on court
"Kiki, she's the best mixed doubles player. She really helps me out on court," the 41-year-old Nestor said. "I actually have to cover less of the court, which is perfect for me, because I'm so old."
Nestor has won all four majors in men's doubles. This was his second Australian Open mixed doubles title after his victory at Melbourne Park in 2007. Sania won the title here in 2009 with Mahesh Bhupathi.