Millwall gained a crucial three points in the Sky Bet Championship on Saturday afternoon as The Lions defeated promotion-chasing West Bromwich Albion 2-0.
Ryan Tunnicliffe gave The Lions the lead on the half-hour mark, with Ahmed Hegazi poking the ball into his own net for Millwall's second halfway through the second-half. Hegazi was then sent off for two bookable offences as the home side secured a much-needed clean sheet.
Jay Rodriguez also missed a penalty for the visitors.
Lions boss Neil Harris opted to field the same XI as in last weekend's trip to Leeds United, whilst there was one change on the bench, as Jiri Skalak came in for Shaun Hutchinson.
The first chance of the afternoon came with three minutes on the clock and went the way of Millwall, but after some patient build-up play, Jed Wallace's burst into the penalty area ended with his effort harmlessly sailing over the crossbar.
The Lions' typical fast start had startled West Brom, who were yet to penetrate the Millwall area, and on 10 minutes the home side should've had the lead, but Lee Gregory blazed over after Ben Thompson's superb work down the right-hand side.
From there The Baggies were able to sustain a spell of pressure, forcing a number of free-kicks and corners, but Millwall stood firm to the onslaught.
The game was opening up as the clock ticked towards the half-hour mark, with the next chance going the way of the visitors - Hal Robson-Kanu's shot, however, was weak and blocked by Jake Cooper, before Rodriguez fired wide.
On 30 minutes, The Lions took the lead. Gregory plucked Dave Martin's kick out of the sky and fed Jed Wallace, who in turn fed Tunnicliffe, who struck under the grasp of Sam Johnstone.
The lead could have been doubled just three minutes later, but Johnstone was equal to Cooper's header from a corner-kick, before Ryan Leonard's follow-up was cleared off the line by Mason Holgate. Jed Wallace's spectacular curler than had Johnstone scrambling to palm away as The Lions' tails were clearly up following the opener.
Martin had to be on guard to expertly tip over Stefan Johansen's effort shortly before the 45-minute mark, whilst the first chance of the second-half went the way of Millwall, but after Ben Marshall's determination allowed Thompson to set up Jed Wallace, his goal-bound effort was blocked.
Leonard then shot wide with 53 minutes on the clock, with West Brom's best chance to date coming four minutes later after Mahlon Romeo misjudged a headed clearance. Robson-Kanu set his sights on goal, but James Meredith's outstanding challenge prevented the Welshman from getting a shot away.
The Baggies were awarded a spot-kick on the hour mark as Cooper's clumsy foul on Dwight Gayle was punished by referee James Linington, but after Rodriguez stepped up to take, he skewed his effort completely wide of Martin's post.
Gayle stole the ball on the by-line on 65 minutes and fed Rodriguez, but after the attacker, determined to make amends, danced his way through bodies in the area, Martin stood tall to block behind.
That was to prove key two minutes after, as after Jed Wallace's ball forward found Thompson, the midfielder's cross from an acute angle was bundled into the net by a Baggies defender to double Millwall's lead.
It should have been three with 16 minutes remaining, but after Thompson's long-range effort was palmed away by Johnstone, the goalkeeper reacted superbly to deflect Gregory's follow-up effort behind. Jed Wallace then robbed Chris Brunt of possession and passed to Thompson, but his shot was sliced over.
With 10 minutes to go The Baggies were reduced to 10 as Hegazi - who had already put the ball in his own net for Millwall's second of the afternoon - fouled Gregory and then stupidly decided to boot the ball into the crowd. Two bookable offences on their own, but certainly enough to allow the referee the option to show his red card.
From there, The Lions held on to comfortably gain a priceless win.
Millwall: Martin, Meredith, Cooper, J. Wallace (O'Brien 85'), Thompson, Gregory, Romeo, Pearce, Tunnicliffe, Leonard, Marshall. Subs not used: Archer, McLaughlin, Williams, Skalak, Elliott, Morison.
Scorer: Tunnicliffe 30', Hegazi (og) 67'
Booking: Meredith, Cooper, Leonard
West Bromwich Albion: Johnstone, Robson-Kanu (Murphy 72'), Johansen, Livermore, Brunt, Townsend, Gayle, Rodriguez (Mears 85'), Adarabioyo, Hegazi, Holgate. Subs not used: Gibbs, Leko, Edwards, Bond, Harper.
Booking: Johansen, Hegazi, Adarabioyo
Sent Off: Hegazi
Referee: James Linington
Attendance: 15,303 (2,018)