Wes Harding then diverted Broadhead's centre into his own net from close range, before Kieffer Moore's downward header from Harry Clarke's super far-post cross looped over Sarkic in first-half-stoppage time.

Millwall looked to salvage some pride after the break as Ipswich eased off, but it was the visitors who struck a stoppage-time fourth when Murray Wallace brought down Ali Al-Hamadi, who rolled in the resulting penalty.

Victory was just Ipswich's second in 10 league matches and was crucial, capitalising on Southampton's defeat at Bristol City on Tuesday to move within a point of the third-placed Saints, and three off Leeds in second, with a game in hand.

In contrast, Millwall look to be sliding towards a battle for survival as a fifth defeat in a winless six-match league run has them just a place and four points above the relegation zone.

Despite their struggles, the hosts pounced on another sluggish Ipswich start as George Saville's clean strike and Ryan Leonard's low shot forced uncertain saves from Vaclav Hladky following an early barrage of set-pieces.

Yet their confidence visibly drained as Ipswich hit their stride, inspired by the excellent Broadhead, whose goal and assist in the space of eight minutes - having seen an earlier goalbound effort deflected over - put the visitors in control.

Having fallen behind in their previous five matches, the platform allowed Town to showcase their skills in Kieran McKenna's 100th league game in charge, and there looked no way back when Moore claimed his third goal in as many games.

Zian Flemming saw an effort diverted wide and Tom Bradshaw forced Hladky into action as Millwall reacted to boss Joe Edwards' half-time talk, but Town looked happy to save their energy for future battles and hit their hosts on the break.

Jeremy Sarmiento fired Wes Burns' cutback narrowly wide from close range, before Al-Hamadi added extra gloss to an excellent night for the Tractor Boys - although Wallace's challenge which conceded the spot-kick looked to have been made outside of the box.

Millwall manager Joe Edwards:

"It is a bit of deja vu. We started well with a clear plan that the players were executing. Their goalkeeper had a few saves to make early on.

"When you play against a team like Ipswich's level, they can score goals at any time but the manner of that [first] goal can't happen.

"It is a combination of things that throws us, we were feeling in a good place, with momentum and then the wind is taken out of your sails with a poor goal, and from there until half-time it just unravelled."

Ipswich Town boss Kieran McKenna told BBC Radio Suffolk:

"I knew it wasn't far away from how we've been going. There has been a lot of misfortune coming our way and tonight we got our fair share of the game and I think we were good value for the win.

"Early in the game if they get a set-play one can lead to two, can lead to three, because they put it in the box at every opportunity that they get.

"We saw that first phase off pretty well and defended the first contacts well all night, and once we got through that and settled on the ball then I thought we controlled the large majority of the game."