Camacho trebled his tally for the season with a brace in the opening 32 minutes, and while Duda was sent off after the break, Celta never threatened a comeback.
In an even start to the contest, each side hit the crossbar in the opening 20 minutes, with Celta midfielder Michael Krohn-Dehli rattling the woodwork with a shot on the turn from 20 yards.
After Celta goalkeeper Yoel could only parry a shot from Santa Cruz back into the danger zone, Camacho was the quickest to react and pounced on the rebound to net for the first time in 2014.
Duda supplied him with Malaga's second by flighting a free kick into the box for Camacho to head into the bottom corner, but the provider of the goal was later sent off for two bookable offences.
His first yellow card was for dissent, and the midfielder was then given his marching orders on 66 minutes when he scythed down Rafinha, giving the hosts 25 minutes to try to find a way back into the match.
Malaga are now 12th in the La Liga table, one point behind Celta.