Three Aussies were in first-round action on Day 2 of Roland Garros, but it could not have gone much worse from an Australian perspective as all of them lost in straight sets.
Millman bowed out 6-3, 6-2, 7-5 to this month's US Open semi-finalist Pablo Carreno Busta of Spain.
Earlier, James Duckworth lost to American Tommy Paul 6-2, 6-3, 6-2 and Aleksandar Vukic went down 7-5, 6-4, 6-0 against Spaniard Pedro Martinez Portero.
It leaves Alexei Popyrin and Marc Polmans as the only Aussie men left flying the flag at this year's tournament.
They face South African Lloyd Harris and Ugo Humbert of France respectively on Day 3.
Watch Day 3 of the French Open LIVE and FREE from 10pm on SBS On Demand, before coverage continues on SBS at 10:30pm.