Mason Saunders-Henry's penalty-kick was a mere consolation for Millwall's Under 23s on Thursday afternoon as Kevin Nugent's side lost 2-1 to Bristol City.
Ricardo Rees and Sam Bell put The Robins two to the good before half-time, with Saunders-Henry reducing the arrears on the hour-mark from the spot.
The young Lions' attempts to get back into the game were valiant, but they were unable to find that elusive second and equalising goal.
Next up for the Under 23s is a home game with Cardiff City at Calmont Road on Monday 18th February.
Millwall: Wright, Harvey, Tiensia, Hanson, Parker, Toppalloj, Mitchell (Duncan 68'), Wicks (Skeffington 80'), Alexander, White, Saunders-Henry (Taylor 70'). Subs not used: Fanshawe, West.