Millwall's Under 23s were 2-0 victors over Birmingham City in the Professional Development League on Saturday afternoon.
Samuel Faniyan and Mason Saunders-Henry - from the penalty spot - were on target as The Lions won at the St Andrew's Trillion Trophy Stadium for the second time in three days.
With 24 minutes on the clock, a corner-kick was headed back across goal and into the path of Faniyan, who bundled home from close range to open the scoring.
Then, 13 minutes later, Saunders-Henry stepped up to convert from 12 yards to double the advantage and secure all three points.
Kevin Nugent's side have four matches remaining in their season, beginning with the visit of Barnsley to The Den on Friday afternoon. Ticket details will be confirmed in due course.
Millwall: King, Muller, Tiensia, Donovan, Debrah, Parker, Duncan, B. Mitchell (Skeffington 77'), Taylor, Faniyan, Saunders-Henry (Davis 52'). Subs not used: Topalloj, Wright, Strachan.