Goals from Jed Wallace and George Saville secured a 2-1 victory for Millwall over Middlesbrough in the Sky Bet Championship at The Den on Saturday afternoon.
Stewart Downing halved the deficit midway through the second-half, but The Lions held firm to claim another three points on home soil.
Lions boss Neil Harris made one change from last Saturday's goalless draw at Aston Villa, as Jordan Archer returned in goal at the expense of David Martin, who dropped to the bench.
The home side soaked up some early pressure and fashioned the first chance of the afternoon on 4 minutes, but Aiden O'Brien's shot sailed over the crossbar. Meanwhile, Patrick Bamford tamely fired wide in Boro's first opportunity at goal.
The visitors were dangerous on the break and could have taken the lead on 15 minutes, but Archer was well placed to keep Bamford's effort out. With 18 minutes on the clock, Shaun Hutchinson powerfully met George Saville's corner-kick, but his header was saved by Darren Randolph.
Four minutes later, the same combination nearly nudged The Lions in front, but after Randolph tipped the defender's header away from goal, Lee Gregory was unable to convert under pressure.
Boro had the ball in the net on 28 minutes, but Britt Assombalonga was correctly ruled offside. The striker had another chance to score just a minute later, but he was unable to meet Downing's dangerous free-kick.
On 31 minutes, The Lions - perhaps against the run of play - took the lead. Gregory's lay-off found Ryan Tunnicliffe, who expertly slid the ball into the path of Wallace, springing the offside trap to slot under Randolph.
Steve Morison's long-range effort on 37 minutes sailed straight into the arms of the goalkeeper, but just seconds later, the lead was doubled through Saville. Initially, it looked as though the midfielder had taken too long in having a shot on goal, but the leading goalscorer somehow danced past a couple of Middlesbrough defenders and fired home for his seventh goal of the campaign.
Millwall were now rampant and could have had a third on the break through O'Brien, but the Irishman's effort was blocked away for a corner-kick.
In the final action of the first-half, Gregory's deflected shot was saved, whilst Boro found the CBL Lower tier with a shot that failed to trouble Archer.
On 56 minutes, Middlesbrough could - and should - have reduced the arreas, but Martin Braithwaite's deft header glanced past Archer's post.
On 67 minutes, with The Lions dominating, Boro got themselves back in the game, as Archer failed to stop Downing's powerful effort from hitting the back of the net.
Shaun Williams made his return to The Den with 74 minutes on the clock as he replaced Gregory, whilst four minutes later, Tunnicliffe had the chance to put the game beyond doubt, but the midfielder failed to make a proper connection with Steve Morison's cross.
Fabio struck over the bar with nine minutes remaining as the visitors looked for the equaliser, but it was Millwall who could have scored the fourth goal of the game through Morison as he latched on to a loose back pass - unfortunately, Randolph rushed out to save. Saville's weak shot then apologetically rolled into the arms of the stopper.
The Lions were throwing their bodies on the line in the final few minutes of the game, with a combination of Mahlon Romeo and Hutchinson blocking Rudy Gestede from equalising.
After surviving four minutes of injury-time, Oliver Langford blew his whistle to cheers around The Den - The Lions have now gone three matches unbeaten.
Millwall: Archer, Meredith, Hutchinson, Gregory (Williams 74'), Romeo, Wallace, Tunnicliffe, Morison, O'Brien (Craig 86'), Saville, Cooper. Subs not used: Martin, McLaughlin, Thompson, Elliott, Twardek.
Booking: Gregory, Romeo, Wallace, Meredith
Scorer: Wallace 31', Saville 37'
Middlesbrough: Randolph, Fabio, Ayala, Gibson, Leadbitter, Assombalonga, Braithwaite (Johnson 80'), Bamford, Howson (Gestede 59'), Downing, Christie (Traore 80') . Subs not used: Konstantopoulos, Shotton, Forshaw, Friend.
Booking: Braithwaite, Leadbitter
Scorer: Downing 67'
Attendance: 12,026 (1,590)
Referee: Oliver Langford