The eighth seeded Indo-Polish pair overcame the Belarus-Spanish combine 6-4 7-5 in the quarterfinals of the USD 7,021,335 hard court tournament.
Bopanna and Kubot saved all three breakpoints they faced in the one hour 15 minutes match and saving a set point in the 10th game of the second set proved crucial in the outcome of the match.
Bopanna, who has not played with Florin Mergea after the US Open, had won the Madrid Masters which was his best performance this season.
They next face sixth seeds Marcelo Melo and Raven Klaasen.