Preston extended their unbeaten run to 24 matches with a comfortable victory over Luton, who had manager Mike Newell sent to the stand and goalkeeper Marlon Beresford sent off.
North End's have not been defeated since their 3-0 loss at Kenilworth Road in September.
This win saw a first goal for the club from Lewis Neal and a David Nugent strike give the hosts a comfortable lead, before Tyrone Mears scored at each end in the space of two minutes in the closing stages.
Defeat was a major blow to Luton's own hopes for a top-six finish.
Town have now lost nine of their last 13 matches and are 10 points behind North End.
Newell, who rejected the overtures of Leicester in the week, took exception to a booking for striker Steve Howard's booking for a challenge on Paul McKenna and after a warning, referee Darren Drysdale banished him from the dug-out just before the interval.
His side were already a goal down following Neal's clinical finish, with Nugent adding a second with a low header shortly after the break.
The Hatters had a glimmer of hope when Ahmet Brkovic's strike came back off the bar and deflected in off Mears, but the versatile defender quickly made amends with a low finish at the other end.
Chris Sedgwick added a fourth from the spot after Beresford's challenge on Mears, which also earned the stopper a red card and saw Kevin Nicholls go in goal for the visitors, who conceded a fifth from substitute Claude Davis.
North End started with plenty of confidence, keeping the ball for long periods but Luton's David Bell had the first real chance, forcing a low save from Preston goalkeeper Carlo Nash after a quick Town counter-attack.
Despite their slick passing play, the hosts were struggling to create chances but in the 20th minute, Neal broke the deadlock in some style. Youl Mawene's lofted ball forward was flicked on by Ormerod and Nugent and controlled by Neal, who skipped past Heikkinen and guided his shot low past Hatters goalkeeper Beresford.
Luton started the second half brightly and Nash did well to block an effort from substitute Leon Barnett, who had a second shot cleared.
Nash also came to the rescue when Rowan Vine cut in from the left and drove towards to the top right corner, only for the North End goalkeeper to push the ball around the post.
But just when Town were getting a foothold in the game, they found themselves two goals down.
McKenna slipped the ball through to Chris Sedgwick wide on the right and his cross was headed in at the far post by Nugent, for his eighth goal of the season.
Vine, who had talked himself into a booking, had another rifled strike held by Nash, with North End increasingly happy to close the game out.
Barnett was denied again by Nash with nine minutes remaining, shortly after Brkovic's drive had hit the bar and bounced back into the goal off Mears in the 82nd minute.
But just a couple of minutes later, Mears restored the advantage with a neat strike from substitute Patrick Agyemang's cross.
Drysdale had no hesitation in pointing to the spot after Mears was hauled down by Beresford and Sedgwick put the spot-kick past Nicholls.
In stoppage time, Nicholls parried a long-range drive from Mears, and Davis was on hand to score with a low finish.
Preston Nash, Mears, Mawene, Lucketti, Hill, Sedgwick,McKenna (Davis 66), O'Neil, Lewis Neal (Whaley 72),Nugent (Agyemang 81), Ormerod.
Subs Not Used: Dichio, Stock.
Booked: Hill, Whaley.
Goals: Lewis Neal 20, Nugent 53, Mears 84, Sedgwick 90 pen, Davis 90.
Luton Beresford, Foley, Coyne (Barnett 41), Heikkinen,Keane (Davis 71), Edwards, Nicholls, Bell (Morgan 59), Brkovic,Vine, Howard.
Subs Not Used: Brill, Showunmi.
Sent Off: Beresford (89).
Booked: Howard, Vine.
Goals: Mears 82 og.
Att: 15,237
Ref: D Drysdale (Lincolnshire).