Ian Henderson scored twice as Rochdale made it three successive wins in 2015 with victory against Crawley.
Scott Tanser volleyed Rochdale ahead before Henderson poked in from a tight angle to make it 2-0 before the break.
Lanre Oyebanjo fouled Matt Done, who saw his spot-kick saved by Lewis Price.
Crawley pulled one back through Marvin Elliott but Henderson slotted home his second before Calvin Andrew got the fourth when the ball cannoned into the net from his charge down.
Rochdale move into the League One play-off places while Crawley have now gone 11 league games without a win.
Rochdale assistant manager Chris Beech told BBC Radio Manchester:
"We did score four goals at Crawley away but that meant nothing because that was just an excellent elite performance for Rochdale that day.
"That's Dean Saunders' first defeat - he's had two really good draws so we knew that they'd be fighting."
Crawley Town interim manager Dean Saunders told BBC Surrey:
"You look at the scoreline and it looks like we've been battered but it didn't tell the true story.
"We've had three great chances at 2-1 and we could've got away with a draw. Izale McLeod, Matt Harrold and Marvin Elliott all missed an open goal.
"We might have gone on and won the game, daftly enough. At least the players didn't cave in.
"I've got a bit of work to do. I've got another week's training with the players and we'll only get better.
"The squad is really thin so I've probably got to bring two or three more players in."