Sky Bet Championship leaders West Bromwich Albion were 2-0 winners at The Den on Sunday afternoon.
Filip Krovinovic and Dara O'Shea found the net as The Baggies consigned Millwall to defeat.
Gary Rowett opted for a three-man midfield, with Ryan Woods, Jayson Molumby and Shaun Williams all lining up together in the midfield for the first time. Meanwhile, Aiden O'Brien and Jed Wallace supported Matt Smith in attack.
The game began amidst Storm Ciara, as strong winds and heavy rain battered SE16 - and it was the visitors, who turned The Lions around at kick-off, who began in the ascendancy. A corner-kick that was - eventually - swung to the back post found Semi Ajayi, but he poked his effort wide.
Callum Robinson then took advantage of some slack defending and beat Bartosz Bialkowski, but saw his effort strike the base of the post, before Connor Townsend's half-volley whistled just past the post on 12 minutes.
Millwall's first piece of attacking play, meanwhile, came with 15 minutes on the clock, but after Murray Wallace retreived the ball on the left-hand side and crossed, the Albion defence dealt with the onrushing Williams well.
Jed Wallace then forced Sam Johnstone into a save as The Lions fashioned a long-range free-kick after Molumby's driving run, with the winger presented with a further chance just a few minutes later after Mahlon Romeo's blocked cross broke to him - his effort was over the crossbar, however.
There were 26 minutes played when Hutchinson sliced his clearance clear from a West Brom cross, with the ball breaking to Kyle Bartley - his first-time effort perhaps should have crept in, but instead the ball went wide, much to the relief of Millwall and Hutchinson in particular.
Hal Robson-Kanu then found his way past the last line of defence and struck just after the half-hour mark but Bialkowski gathered, before Krovinovic flashed a ball across the face of goal, only for no West Brom man to take advantage.
Matheus Pereira then tested Bialkowski from range four minutes from the break, but just one minute later, Krovinovic picked the ball up outside the penalty area and guided an effort past the stopper to open the scoring.
A Murray Wallace header then fell fortunately for Robson-Kanu as first-half stoppage-time got underway, but just as the winger was about to pull the trigger, a fantastic challenge from Jake Cooper prevented the lead from being doubled.
Four minutes into the second-half The Baggies nearly scored a second, but somehow the lively Robson-Kanu's shot hit the roof of the net. The Lions continued to probe for an equaliser as Rowett threw on Jon Dadi Bodvarsson and Connor Mahoney, but the next chance went the way of the visitors after they were given a questionable corner - Bartley heading over the back post.
Both Robson-Kanu and Pereira failed to get a shot on target as the final 20 minutes got underway, before Jed Wallace's free-kick was punched away by Johnstone at the other end.
Baggies substitute Matt Phillips was straight into the action after his arrival, beating Murray Wallace for pace and fizzing an effort towards goal, which went over. Jed Wallace then found the ball at his feet on the edge of the area, but his shot was tame and easily claimed by Johnstone.
Tom Bradshaw was brought on in an attempt to get back into the game, but the game was put to bed six minutes from time as O'Shea nodded in at the near post following a corner.
Jed Wallace stung the palms of Johnstone from another free-kick as the game entered stoppage-time before Kamil Grosicki fired over, with referee Gavin Ward blowing his whistle on a home defeat shortly after.
Millwall: Bialkowski, M. Wallace, Hutchinson, Cooper, Williams (Bradshaw 77'), J. Wallace, Smith (Bodvarsson 59'), Romeo, Molumby, Woods, O'Brien (Mahoney 59'). Subs not used: Steele, Ferguson, Pearce, Skalak.
West Bromwich Albion: Johnstone, Robson-Kanu (Austin 90+1'), Bartley, Ajayi, Krovinovic, Livermore, Pereira (Phillips 76'), Townsend, Sawyers, O'Shea, Robinson (Grosicki 66'). Subs not used: Bond, Furlong, Harper, Hegazi.
Scorer: Krovinovic 42', O'Shea 84'
Referee: Gavin Ward
Attendance: 13,818 (1,382)