Rochdale's five game unbeaten run came to an abrupt end after a crushing defeat at Portsmouth.
The impressive Jed Wallace opened the scoring when he picked up the loose ball on the edge of the box and fired into the bottom corner.
Centre back Bondz N'Gala made it two for Pompey as he met a Ricky Holmes corner and headed in from close range.
N'Gala and Holmes then combined again as the defender headed home another Holmes corner to seal the points.
The win is only Portsmouth's second at home this season and maintains an impressive record of never losing to Rochdale.
Dale slip to eighth in League Two while Pompey climb to 15th.
VIEW FROM THE DRESSING ROOM
Portsmouth manager Guy Whittingham told BBC Radio Solent:
"The important thing was that we created chances early on and put them under pressure.
On new keeper (Trevor Carson): "As a goalkeeper you have to stay concentrated for that amount of time...he's put in a steady performance and right at the death he's made two great saves.
"That's a performance that a Portsmouth side should be doing week in week out; hard graft, doing the ugly side of football well and I'm glad it's come to the table."
Portsmouth 40 Carson 06 Bradley Booked 05 Devera 14 Painter Booked 03 N'Gala 11 Holmes 35 Wallace Booked 13 Ertl Booked 31 Racon (Padovani - 79' ) 23 Agyemang (Barcham - 80' ) 32 Marquis Substitutes 10 Craddock 20 Cooper 08 Padovani 34 Butler 15 Mahon 01 Smith 07 Barcham Rochdale 01 Lillis 25 Rose (Vincenti - 59' ) 06 Lancashire 22 O'Connell 03 Bennett Booked 16 Done 38 Dicker (Héry - 63' ) 40 Henderson 12 Lund 11 Hogan 39 Bunney (Cummins - 53' ) Substitutes 07 Vincenti 21 Thomson 02 Rafferty 14 Héry 05 Eastham 29 Cummins 24 Allen
Ref: Simon Hooper