Mark Marshall's goal was only his second of the season for Bradford City
Bradford moved into second place in League One with their biggest win of the season after thrashing Rochdale at Valley Parade.
The result maintained Bradford's unbeaten home record in the league as they bounced back in style from their FA Cup defeat by Accrington.
Bradford took charge of the game with two goals in three minutes towards the end of the first half.
Top scorer Billy Clarke put them in front after 41 minutes with his sixth goal of the season, rifling a right-foot shot into the net after Nicky Law's left-wing cross had been helped into his path by James Hanson.
Clarke was also instrumental in Bradford's second goal three minutes later.
Visiting goalkeeper Josh Lillis dived full length to turn his low 25-yard shot away for a corner and, when Clarke's set-piece was cleared back to him, he returned the ball into the goalmouth for Timothee Dieng to score with a glancing header.
Rochdale were reduced to 10 men after 57 minutes when Niall Canavan was sent off for a second yellow card after bringing down Josh Cullen just outside the penalty area.
Bradford then scored a third goal when the Rochdale defence failed to clear the resulting free-kick taken by Mark Marshall. Hanson's close-range header was blocked by Lillis and the striker scored from the rebound.
The Bantams added a fourth in the 62nd minute when Marshall scored direct from a free-kick just outside the box.
Report supplied by the Press Association.
Rochdale manager Keith Hill told BBC Radio Manchester: "I was really pleased with the first half, regardless of the scoreline, I thought we were superb.
"The second half, it looks a bit chaotic, but when you're playing a team like Bradford, who retain the ball, it's very difficult when you're down to 10 men.
"If you're playing a direct side and you're down to 10 men, you can get something from the game because they constantly give it you back.
"Some of the players have run through a brick wall today, they never stopped trying, the mental condition of the players now is not to give up."
