Ben May made a dream return to first team action as he headed Millwall into the Johnstone's Paint Trophy Southern Section Quarter Final in front of 1,905 hardy fans.
Last season's top scorer May, sidelined since the summer with a shoulder injury, was introduced after the break for Chris Zebroski.
And it took him less than two minutes to make his mark on proceedings, firmly heading Chris Hackett's 47th-minute corner past keeper Neil Moss.
Marvin Williams had earlier breathed life into the game by breaking the deadlock on 20 minutes with a cool finish after Zebroski's cross was deflected into his path.
But no sooner had The Lions established a lead than they were forced to reshuffle when skipper Tony Craig was forced off with a shoulder injury.
Marvin Elliott slotted into midfield with Zoom Bakayogo, who had began to cause a few problems with his pace down the left flank, reverting to one of the three centre backs alongside Richard Shaw and Danny Senda.
Within seconds Lions keeper Lenny Pidgeley was called into action for the first time, parrying a Darren Anderton free-kick for a corner.
Leon Best then tried his luck from 20 yards, but his drive lacked power and was comfortably held by Pidgeley.
Lions caretaker manager Willie Donachie made two changes at the break, bringing on May and also giving a useful run-out to Paul Robinson following his spell sidelined with a hamstring strain.
Once May had added Millwall's second, it was effectively game over as Donachie's side enjoyed the cushion of a two-goal advantage for the first time this season.
May was a whisker away from connecting with Hackett's slide-rule pass and then Samy Mawene drove wide as The Lions went in search of more goals.
Elliott was denied by a great block by Cherries sub Steven Foley, while at the other end Leon Best capitalised on a slip by Robinson, but fired into the side netting.
It took a great reflex save by Pidgeley to deny Anderton, pushing the veteran's first-time shot round the post for a Bournemouth corner eight minutes from time.
Even though The Lions played the final five minutes of the match and subsequent five minutes of injury time with 10 men after Mawene hobbled off, the damage had already been done and there was no way back for Bournemouth.

Millwall: Pidgeley, Senda, Bakayogo, Grant, Craig (Elliott, 25mins), Shaw (Robinson, 46mins), Hackett, Mawene, Williams, Zebroski (May, 46mins), Morais. Subs not used: Day, Whitbread.
Scorers: Williams (20mins), May (47mins)
AFC Bournemouth: Moss, Young, Purches, Best, Hollands, Hayter, Gowling, Hart, Ainsworth (Foley, 54mins), Anderton, Cummings (Songo'o, 46mins). Subs not used: Maher, Fletcher, Stewart.
Bookings: Gowling (32mins), Anderton (77mins)

Ref: Keith Woolmer
Att: 1,905 (Away 137)