PNE 2 Scunthorpe United 0
Johnson collected a clever reverse pass from former Aston Villa team-mate Callum Robinson to scoop the ball home from ten yards out just before the hour mark.
And Robinson was again involved in the build up to the second which eventually saw Chris Humphrey collect a ball pushed wide by Luke Daniels and pull the ball back for Gallagher to slam home at the back post.
Manager Simon Grayson made three changes to the side that faced Manchester United in the FA Cup; Sam Johnstone and Daniel Johnson returning to the starting XI, with Callum Robinson also starting in attack alongside Joe Garner.
It was a slow start to the game, both sides feeling their way into the game, however, North End started to create come good chances around the mid-point of the half.
On 21 minutes Joe Garner was played in by Robinson, a lofted ball to the back post. The 14-goal front man managed to get in a goalbound header, but he was adjudged to be offside.
A good period of pressure followed and Chris Humphrey and Callum Robinson both played dangerous balls into the box, only for Canavan and Boyce to clear from under the noses of the North End forwards.
Just before the half hour mark Chris Humphrey ran at his man down the right and finished with a vicious shot from right hand corner of the box, which was dipping but just over cross bar.
Scott Laird then drove a ball into the box which Garner met on the volley, but the No.14 couldn’t get the power on his effort, even though it was on target.
Six minutes before the break, PNE won their first corner after Callum Robinson did well in the left channel and pulled ball across but Garner scuffed his shot and Canavan scrambled it wide for the Iron.
A change at half-time saw North End change to 4-3-3 with Clarke at right back and Laird on the left.
The visitors had the first real chance of the second half as a deep corner was spilled and came out to Paddy Madden, who shot through a crowd, only for Paul Gallagher to be on the right spot to clear off the line.
But it was North End who had the ball in the back of the net first and it was a former Villa combination. Paul Gallagher did well to run from the middle of the park, dancing past three men before threading it into a left hand channel for Callum Robinson who ran down the left edge of trhe box before pulling it back to the penalty spot to where Daniel Johnson scooped the ball into the bottom right hand corner of Luke Daniels goal.
North Endc pressed immediately for a second, Paul Gallagher seeing a shot well saved by Daniels after Robinson again had played a sublime ball in behind the Iron defence for the fellow on loan man.
Marcus Williams then presented a second as Joe Garner rose highest at the back post to meet Scott Laird’s corner from the right, which was beautifully placed to the back post, however, Williams did well to head clear.
But it was two shortly after with 19 minutes left as Scott Laird was played in down the left, he drilled a ball across the box which was spilled by Daniels, coming out to Humphrey who instead of shooting put the ball back across the six yard box behind Garner but into the path of Paul Gallagher who slammed the ball back into the net for his 12th goal of the season.
It could have been three soon after as Daniels spilled a cross from Robinson and Bailey Wright was on hand to hook the ball goalwards, only for Williams to usher it out for a corner.
Chris Humphrey brought a brilliant save out of Daniel with two minutes left, tormenting Marcus Williams down the right before firing hard towards the top left hand corner, the stopper doing well to push it up and away.
Five minutes were added on by official Kevin Wright, but it was comfortably managed by the Lilywhites who made ground on two of the teams above them.
PNE line-up: Johnstone, Clarke (c), Huntington, Wright; Welsh (Kilkenny, 77); Humphrey, Johnson, Gallagher (Ebanks-Blake, 86), Laird; Garner (K Davies, 86), Robinson. Subs not used: Stuckmann, Wiseman, Kilkenny, Buchanan, Reid.
Scunthorpe United line-up: Daniels, Canavan, Madden, Van Veen (McSheffrey, 46), Bishop (c) (Wootton, 83), Evans (Osbourne, 65), O’Neil, Boyce, Williams, J Clarke, Hopper. Subs not used: Anyon, Nolan, Adelakun, Wootton, Llera.
Attendance: 9,415 (484 away fans)
Referee: Mr K Wright