Sam Winnall scored twice in two minutes as Scunthorpe moved top of League Two with victory over 10-man Rochdale.
The visitors had the best chance of the first half, but Scott Hogan saw his header superbly saved by Sam Slocombe.
Scunthorpe took the lead just before the hour mark as David Syers neatly slotted home from 20 yards out.
Rochdale's Michael Rose was sent off for a second yellow card, as Winnall struck a stunning effort into the top corner before calmly tucking home.
The away side could themselves have moved into first place with a win, but the heavy loss means they are now four points behind their New Year's Day opponents.
VIEWS FROM THE DRESSING ROOM
Scunthorpe United manager Russ Wilcox told BBC Radio Humberside:
"I thought we were terrific for different reasons in the first half, backs to the wall at times, they put a lot of pressure on us.
"They created throw ins, they created corners, they created free kicks and we just weathered it.
"The second half was all about us, our performance, and I don't think you'll see three better goals in one game."
Rochdale manager Keith Hill told BBC Radio Manchester:
"I'd like to talk about their goalkeeper and the two outstanding saves that he's made. I thought he was incredible.
"It's a very, very difficult situation now for me because Michael Rose has got to miss the Leeds game [in the FA Cup third round] as a consequence to being sent off for a second booking.
"I think their bench thought that, at best, it was a foul but never a yellow card. But we just had a crazy 15-20 minutes when every time there was a challenge there was a booking."
Scunthorpe United 01 Slocombe 02 Ribeiro Booked (Esajas - 83' ) 18 Nolan 04 McAllister 05 Mirfin 06 Canavan 14 Hawkridge (Adelakun - 74' ) 24 Syers (Collins - 62' ) 08 Burton Booked 29 Winnall 30 Williams Substitutes 07 Sparrow 09 Iwelumo 10 Esajas 13 Severn 15 Waterfall 16 Adelakun 19 Collins Rochdale 01 Lillis 02 Rafferty 25 Rose Dismissed after an earlier booking 04 Cavanagh Booked (Allen - 72' ) 06 Lancashire Booked 22 O'Connell 40 Henderson 12 Lund Booked 11 Hogan Booked (Done - 71' ) 29 Cummins 07 Vincenti (Donnelly - 64' Booked ) Substitutes 03 Bennett 05 Eastham 09 Donnelly 14 Héry 16 Done 21 Thomson 24 Allen
Ref: Andy Woolmer