Steve Morison's 72nd minute leveller handed Millwall a point in a 1-1 draw at Gillingham on Saturday afternoon at Priestfield in Sky Bet League One.
Joe Quigley gave The Gills the lead in controversial circumstances on 67 minutes, but Morison pounced five minutes later to ensure a share of the spoils.
Neil Harris made two changes to the side that defeated Shrewsbury Town 2-1 on Tuesday night, with Joe Martin and David Worrall coming into the starting XI at the expense of Tony Craig and Shane Ferguson.
The Lions sprung into action immediately and could have taken the lead in the first minute, but after good work from Worrall and Morison, Aiden O'Brien was unable to get a shot away from 12-yards out.
Jed Wallace and O'Brien linked up with 10 minutes on the clock to put Morison on goal, but the striker curled his effort into the outstretched arms of Tomas Holy.
On 24 minutes, Morison's corner found Shaun Williams in space on the edge of the penalty area, but the Irishman's sweet volley agonisingly crept over the crossbar.
Four minutes later, The Lions kept probing and nearly found a way to goal through Morison, but his shot hit the side-netting.
The striker was heavily involved in Millwall's attacking play and again made Holy work just after the half-hour mark following excellent play by Worrall.
The Lions' defence was standing firm at the other end, meanwhile, with Cody McDonald's blocked shot the only effort of note for the home side.
Millwall continued the second-half in the same vain that they ended the first, but could only muster a shot wide from Ben Thompson in the opening 10 minutes.
Harry Cornick thrashed wide for The Gills on 58 minutes as they looked for a way to take the lead. Nine minutes later, they did just that in the most controversial of circumstances.
A long ball forward from Deji Oshilaja saw King gather on the edge of his six-yard box. However, after being pushed off the pitch by a Gillingham attacker, referee Charles Breakspear gave a corner and not a foul.
From the resulting kick, King initially saved well, but Quigley was on hand to poke home the rebound from close range.
Two minutes later, the ball bounced the way of substitute Lee Gregory from a few yards out; unfortunately, the striker was unable to sort out his feet in a split-second decision and shot wide.
On 72 minutes, The Lions grabbed a deserved goal to level the scores through the hard-working Morison.
Good play between Mahlon Romeo and Wallace saw the latter have a shot saved by Holy, but Morison was first to the rebound to fire into the roof of the net.
Both sides huffed and puffed in their attempts to get that crucial winning goal, but in the end, referee Breakspear blew time on an enthralling contest with the score at 1-1 - a result that moves Millwall into the top 6 in Sky Bet League One.
Gillingham: Holy, Jackson, Ehmer, Oshilaja, McDonald, Martin, Quigley, Rehman, Byrne (Osadebe, 79'), Cornick (Hessenthaler, 75'), Wright. Subs not used: Nelson, Donnelly, Parker, List, Muldoon.
Scorer: Quigley (67')
Bookings: Martin, Byrne, Wright
Millwall: King, Martin, Hutchinson, Williams, Worrall (Onyedinma, 87'), Thompson, Romeo, Wallace, Webster, Morison, O'Brien (Gregory, 65'). Subs not used: Girling, Cummings, Butcher, Cooper, Abdou.
Scorer: Morison (72')
Referee: C. Breakspear
Attendance: 7,221 (2,262)