The second seeded Bopanna-Ebden pair lost 1-6 5-7 to the 16th seed Argentine combo of Maximo Gonzalez and Andres Molteni in 66 minutes on Sunday night.
As Alcaraz and Sinner, two of the men at the vanguard of tennis's new generation moved on, 37-year-old Andy Murray kept his fans guessing over his participation