Charleston (US), April 11 (IANS): Sania Mirza and Martina Hingis secured the No.1 position on the doubles leaderboard for the end-of-season tennis championships after defeating Spain's Anabel Medina Garrigues and Kazakhstan's Yaroslava Shvedova in the quarter-finals of the Family Circle Cup.

The No.1-seeded Hingis and Mirza battled Medina Garrigues and Shvedova for an hour and 41 minutes for a 7-5, 4-6, 13-11 victory, fighting off a match point down 10-9 in the match tie-break and needing six match points of their own to edge the Spanish-Kazakhstani defending champions on Friday.

Their latest win ensured that they will overtake Australian Open champions Bethanie Mattek-Sands and Lucie Safarova (currently No.2) and Russians Ekaterina Makarova and Elena Vesnina (currently No.1) in the doubles leaderboard, according to the Women's Tennis Association's (WTA) website.

The end-of-season WTA Finals will be played in Singapore from October 25 to November 1.

Mirza, currently No.3 in the individual rankings for doubles players, will become the top-ranked player if she and Hingis manage to win the Family Circle Cup.