The 42-year-old Bopanna and his Dutch partner Matwe Middelkoop, seeded ninth, were stunned by the unseeded Italian pair of Andrea Vavassori and Lorenzo Sonego (2) 6-7 2-6.
It turned out to be a woeful day for Bopanna and China’s Yang Zhaoxuan, seeded sixth, as they went down 5-7 5-7 to Australia’s Max Purcell and Gabriela Dabrowski in the first round of mixed doubles.
Earlier in the day, Ramanathan and Serbia’s Nikola Cacic lost 4-6 4-6 to the Italian combination of Simone Bolelli and Fabio Fognini, the 15th seeds, in men’s doubles.