The Lions were in front as early as the fifth minute when Danielle Dichio fired Millwall in front. Loan signing Stefan Moore added a second on the stroke of half-time before Paul Ifill effectively sealed victory with the third on 51 minutes.
Wycombe, who included former Millwall captain Stuart Nethercott in their starting line-up, managed to pull one back but never really got back into the game as The Lions strolled to victory.
Millwall: Stack, Dunne, Livermore, Elliott, Ward, Dolan, Ifill, Morris, Moore, Dichio, Sweeney. Subs: Harris, Marshall, Cogan, Weston, Wise.