Sania and Tecau defeated the Australian pair of Jarmila Gajdosova and Matthew Ebden 2-6, 6-3, 10-2 in a contest lasting an hour and 13 minutes.
In a see-saw battle, Sania and Tecau were outplayed in the opening set, during which they failed to earn even a single break point. Gajdosova and Ebden were markedly better with their first serve to pocket the opener in 28 minutes.
But Sania and Tecau roared back into the match in the second set. The Indo-Romanian pair held serve and converted the only break point they earned.
They were also helped by the nine unforced errors, which their rivals committed, to stay afloat in the match. Sania and Tecau were immaculate in the decider and did not commit a single unforced error en route to outwitting the local favourites.
Sania and Tecau will be up against the winners of the clash between Sino-American pair of Jie Zheng and Scott Lipsky and the French-Canadian combination of Kristina Mladenovic and Daniel Nestor.
If Sania and Tecau win the summit clash, it would be the Indian's second Australian Open mixed doubles title. Sania had earlier won the trophy with Mahesh Bhupathi in 2009.