Goals from Lee Gregory and Ben Marshall earned Millwall a 2-0 victory at Barnsley in the Sky Bet Championship on Saturday afternoon.
The win at a bitterly cold Oakwell equals a club record of consecutive League away wins, set in 2008/9 and also stretches the club's unbeaten run to 12 matches.
Gregory pounced on some slack defending to give Millwall the lead midway through the first-half, before Marshall curled a beauty into the top corner after the hour to make the points secure.
Neil Harris made one change to his matchday squad, with Aiden O'Brien returning from injury to take his place on the substitutes' bench at the expense of Conor McLaughlin - the starting XI remained the same as last Saturday's 1-0 defeat of Brentford at The Den.
Millwall started fast and attacked down their right-hand side, but twice Liam Lindsay stopped Jed Wallace getting a cross into the box. Oliver McBurnie had The Tykes' first effort of the afternoon but it was blocked away for a corner-kick.
On 17 minutes, a lucky ricochet allowed Mamadou Thiam to cross, but Jake Cooper was well placed to turn the ball over the crossbar. The resulting corner was cleared away, with Kieffer Moore heading into the arms of Jordan Archer shortly after.
On 24 minutes, The Lions took the lead. Wallace pounced on some dodgy Barnsley defending and slid the ball into the path of Gregory, who poked home past Nick Townsend at the first attempt to open the scoring.
Soon after, Wallace fired a ball across the box, but to no avail. As the half-hour mark approached Gary Gardner let fly from distance, but his effort found the stand behind the goal. With 34 minutes on the clock Millwall could have doubled their lead, but after Gregory rounded Townsend, George Saville's shot went over the bar.
Ben Marshall's tame effort was saved and Lindsay headed over the bar in what should have been the final action of the first-half, but when more slack Tykes defending allowed Steve Morison in on goal, he somehow conspired to miss the ball completely, shooting at thin air.
The second-half was three minutes old when Barnsley had a chance to equalise, but Archer tipped Lindsay's shot around the post and behind. The Tykes had a further opportunity with 58 minutes on the clock, but the stopper was once more on hand to save from Moore's header.
On 63 minutes, The Lions doubled their lead in outstanding circumstances. Good work from Wallace saw the winger lay the ball into the path of Marshall - the Wolves loanee steadied himself before curling a beautiful effort into the top corner beyond the reach of Townsend.
Barnsley's attempts to get back into the game were thwarted by Archer once more, this time from substitute George Moncur, whilst Gregory's shot was saved by Townsend as Millwall looked for a third.
McBurnie looked to halve the deficit on 74 minutes, but Jake Cooper brilliantly raced back to hook the ball off the line, before Archer saved Thiam's powerful effort.
As a snowstorm engulfed Oakwell, The Lions held firm to secure the record and another three points on the road.
Barnsley: Townsend, Yiadom, Jackson, Lindsay (Isgrove 81'), Pinillos, Gardner, Potts (Bradshaw 66'), Mallan (Moncur 46'), Moore, Thiam, McBurnie. Subs not used: Walton, Cavare, Mahoney, Pearson.
Millwall: Archer, Meredith, Hutchinson, Williams, Gregory (Shackell 74'), Romeo, Wallace, Morison (Cahill 90'), Saville, Cooper, Marshall (Onyedinma 79'). Subs not used: Martin, Tunnicliffe, Elliott, O'Brien.
Scorer: Gregory 24', Marshall 63'
Referee: P. Bankes.