Two goals from Chris Taylor and Steve Morison's 18th goal of the season all but confirmed Millwall's place in the League One Play-Offs as The Lions returned to winning ways on the road with a hard-fought success at Gigg Lane.
Millwall got off to a dream start with less than four minutes on the clock courtesy of Taylor's second goal in a Lions shirt before Morison made it 2-0 on 33 minutes. Bury's Ryan Lowe reduced the arrears in first-half injury-time with the 200th goal of his career only for Taylor to produce a killer third goal seven minutes from time.
The Lions, who had not tasted victory on their travels since a 1-0 result at Rochdale five away games ago, found that winning touch at a critical time of the campaign and know now that one point from the last two games will officially clinch a Play-Off place.
Manager Neil Harris gave Fred Onyedinma his first League One start since 26th March in place of Lee Gregory in an otherwise unchanged team from the side that started against Fleetwood.
However the visiting goal led a charmed life with just three minutes on the clock. A quick break down the right saw the ball worked to Danny Pugh, whose stinging low drive was palmed away by keeper Jordan Archer at full stretch. In the ensuing scramble Mark Beevers headed off the line before Joe Martin eventually booted the loose ball clear of the danger zone.
Play quickly swung up the other end and Taylor's effort was turned behind by Shakers' keeper Chris Neal for the first corner of the game. Taylor shaped up to take the dead-ball and his delivery from the left curled over a condensed six-yard box and dropped into the back of the net.
Back came Bury looking for an immediate response and Archer was forced into action on 10 minutes with a smart save on the line from Craig Jones' dangerous cross. Ben Thompson then reminded the home side of Millwall's attacking threat and when the diminutive midfielder was played in by Jimmy Abdou, he took aim from 25 yards with a thunderbolt that flashed narrowly over the bar.
Onyedinma then robbed Chris Hussey on the right but his cross, aiming for Aiden O'Brien, was collected by the keeper before Taylor was denied a second goal on 17 minutes when his fierce drive was cleared off the line by Peter Clarke.
In a really open first-half both teams continued to trade scoring chances with Archer smartly stopping Hussy's low cross and then collecting Danny Mayor's shot after he had weaved his way into the penalty area.
There was no shortage of action at the other end and Clarke's clearance cannoned off Lions goalscorer Taylor to force Neal into a good save, with the keeper also keeping out Morison's follow-up shot.
Another goal was always on the cards in an entertaining game and it went Millwall's way after 33 minutes. A neat one-two between Morison and Taylor saw the former thread a neat angled finish into the back of the net for goal number 18 of an increasingly productive season.
That two-goal cushion looked to have put The Lions in full control as the game headed towards the final five minutes of the half. Bury, however, had other ideas and really started to turn the screw in a spell that saw Abdou clear Cian Bolgar's goal-bound effort off the line and some brilliant defender by Byron Webster, going shoulder to shoulder with Tom Soares in the penalty area, use his sheer strength and positioning to avert the danger.
The home side gave themselves a foothold back in the game on the stroke of half-time when John O'Sullivan worked an opening on the right and delivered an inviting cross that Lowe smashed home high into the roof of the net to reduce the deficit to a 1-2 scoreline.
Not surprisingly Bury started the second half on the front foot with Mayor, in particular, asking questions of the visitors defence. Yet again, though, Harris' men weathered the storm and remained cool and calm under pressure before starting to create chances of their own.
A great piece of interplay involving Morison and O'Brien so nearly conjured a third goal for Millwall 18 minutes time. Skipper Morison nutmegged his marker and slipped the ball to O'Brien, picked up a return pass and saw his shot blocked on the line with sub Ed Upson heading the loose ball inches wide of the upright.
At the other end a wonderful double save from Archer kept Millwall's slender advantage intact five minutes later using both hands to punch a 20 yard rocket from sub Sean Clare away from his goal. The ball spun up and Archer then acrobatically punched clear to protect his goal expertly.
The Lions responded and Soares was booked following a crude challenge on Taylor as the Lions man looked to lead a counter attack, breaking clear on the halfway line before his run was brought to a halt.
Skipper Morison, who produced a supreme performance up front, was involved in the thick of the action once more and his neat 81st-minute through ball to Joe Martin ended with the left-back's dangerous cross headed clear for another corner. From Taylor's delivery, Morison's header was cleared off the line and Webster's follow-up effort snacked the woodwork.
The Shakers were rattling defensively and The Lions ruthlessly took advantage by adding a third goal to finally give Harris' men the breathing space they both craved and deserved.
Brilliant work by Morison on the left set up Taylor, who picked up a perfectly weighted pass from his captain and rifled an unstoppable shot home through a crowd of players to the delight of both the travelling fans, and former Den favourite Tony Warner, who was at the game and gleefully joining in the celebrations!
Taylor was now in the hunt for his first ever hat-trick in a Millwall shirt and was denied four minutes from time when a crisply struck 18-yard shot was cleared by a clearly beaten Bury side.
To put the icing on the Millwall cake, Tony Craig came on in the first minute of injury time to make his first senior appearance since sustaining an injury at Peterborough in October. It might only have been a two minute appearance, but to have another experienced player back at such a crucial stage of the season was the perfect ending to a thoroughly satisfactory afternoon at Gigg Lane.
Neal, Hussey, Clarke, Mayor, Pope, Jones, Lowe (Rose, 74mins), O'Sullivan (Clare, 67mins), Soares, Pugh, Bolgar. Subs not used: Lawlor, Sedgwick, Rose, Brown.
Booking: Soares (79mins)
Archer, Romeo, Martin, Webster, Beevers, Thompson, Abdou, Onyedinma (Upson, 59mins), O'Brien (Philpot, 87mins), Morison (Craig, 90+1min), Taylor. Subs not used: Forde, Edwards, Twardek, Nelson.
Taylor (62mins), Martin (64mins)
Taylor (4, 83mins), Morison (33mins)