Wimbledon, July 8 (IANS): The Indo-Romanian tennis duo of Rohan Bopanna and Florin Mergea caused one of the biggest upsets of Wimbledon when they ousted men's doubles top seeds Mike and Bob Bryan to enter the semi-finals of the lone grass court Major at the All England Club here.

Seeded ninth, Bopanna and Mergea stunned the veteran Americans 5-7, 6-4, 7-6(9), 7-6(5) in two hours and 35 minutes to book place in the last four of the tournament on Tuesday. Next up, they will take on fourth seeds Jean-Julien Rojer of the Netherlands and Horia Tecau of Romania.

Earlier, India's Sania Mirza, partnering Brazil's Bruno Soares, entered the mixed doubles quarter-finals. The second seeds defeated Croatian duo of Marin Draganja and Ana Konjuh 6-3, 6-7(5), 6-3 in a third round match that lasted an hour and 38 minutes to seal their place in the quarters. They will next meet fifth seeds Austro-Hungarian pair Alexander Peya and Timea Babos.

Coming back to men's doubles, the Bryan brothers started the match on an aggressive note, winning 24 of 28 first serve points and breaking their opponents once to take the first set.

The second set saw the ninth seeds making a strong comeback by breaking their opponents twice in comparison to the Bryans breaking Bopanna and Mergea only once. The Indo-Romanian combine won the set to level the match.

The Bryan brothers, ranked No.1 and 2 in the world, came back strongly in the third set but the ninth seeds were good enough to force the set into the tie-break. Bopanna-Mergea played brilliantly to win the tie-break 11-9 and and take a 2-1 lead in the match.

The fourth set also went to a tie-break as Bopanna-Mergea held on their serve comfortably. In the crucial breaker, Bopanna and Mergea did well to come out on top 7-5 and seal the match in their favour.

Elsewhere, Mirza and Soares started their third round campaign on a positive note, winning 13 of 15 first serve points and also breaking their opponents once to go one set up by 6-3. Draganja and Konjuh came back to take the second set into tie-break and won it to level things up.

The third and final set saw the second seeds play more aggressively in their quest for the quarters berth. The pair broke their opponents once and two double faults by Draganja and Konjuh made it easy for the Indo-Brazilian pair to win the set 6-3 and advance to the last eight.

In boys' doubles, India's Sumit Nagal and Vietnam's Nam Hoang Ly defeated Australia's Alex de Minaur and Japan's Yosuke Watanuki 6-4, 7-5 in the opener to enter the second round. In the girls' singles second round, India's 15th seed Pranjala Yadlapalli lost to United States' Michaela Gordon 2-6, 3-6.