Sania Mirza and her Russian partner Elena Vesnina clinched their second WTA title together, lifting the Family Circle Cup doubles trophy with a straight-set triumph over Americans Bethanie Mattek-Sands and Meghann Shaughnessy in Charleston.The unseeded Indo-Russian pair beat the fourth seeds 6-4 6-4 in what was a repeat of the Indian Wells final three weeks ago in which Sania and Vesnina had come out victors.