The Scot then added some gloss to a brilliant 45 minutes when his through-ball was followed by a cheeky finish from Sean Maguire to put the game to bed, before Ben Thompson's second-half consolation.

Millwall came into the game buoyed by successive away victories against AFC Wimbledon and Derby County in the FA Cup and Championship respectively.

However, it was the Lilywhites that dominated from the off, with the tricky Maguire drifting into space on the left-wing before delivering a pinpoint cross for the arriving Tom Barkhuizen, whose goalbound effort was deflected wide.

Preston's enterprising style was rewarded just a minute later, when Gallagher's free-kick led to pinball and Hughes was on hand to net his second goal against Millwall this season with a lovely measured volley into the corner that gave Jordan Archer no chance.

As the home faithful became increasingly agitated, the Lancashire side doubled their advantage, thanks again to Gallagher's precision.

Millwall committed the cardinal sin of leaving a man free at the back post from a corner and were punished, with Clarke stooping low to head home.

The chasm between the two sides did not look like closing and the contest looked to be all over after 27 minutes.

The third strike was easily the pick of the bunch.

There didn't seem to be anything on for Gallagher as the ball popped up to him 30 yards out, but he spotted Maguire's darting run and a beautifully cushioned through-ball was snaffled up by the Irishman, who kept his composure to impudently dink the ball over a despairing Archer.

Boos greeted the half-time whistle and the second period saw the introduction of Shane Ferguson and Steve Morison, with the former driving a fierce effort past Declan Rudd's left-hand post after 57 minutes.

However, it was Millwall's third substitute Thompson who pulled one back barely a minute after coming on.

An inviting ball to the far post by Ben Marshall was nodded back across goal by Morison where it was buried by the 23-year-old.

Harris' men began almost closed the margin further when Jed Wallace's deflected drive was shovelled away by Rudd, with Lee Gregory's scuffed follow-up rolling agonisingly wide.

For all their second-half intent, the Lions' wastefulness in the final third meant the outcome was never really in doubt.

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