Schalke's caretaker coach trio marked their first home game in charge with victory as Karlsruhe slipped closer to the Bundesliga trapdoor.
Kevin Kuranyi and Jefferson Farfan scored in each half to give Mike Buskens, Oliver Reck and Youri Mulder a second straight win and maintain the hosts' hopes of a European place.
It was a second goal in two games for both strikers, whose erratic form throughout the season undermined the reign of former boss Fred Rutten.
Christian Timm shot wide from 22 yards after seven minutes before Kuranyi settled Schalke's nerves with the opener.
Karlsruhe keeper Markus Miller threw the ball straight to the Germany striker, who drilled a left-footed shot into the top right corner in the 24th minute.
The basement boys came into the game without a goal in seven Bundesliga games, but made a fist of getting back on level terms.
Sebastian Freis and Lars Stindl linked up well to allow Stindl to fire over and the same played had another effort comfortably held by Manuel Neuer a minute before the interval.
Karlsruhe continued to pose a threat after the break and Neuer was again on hand to cut out a cross from Antonio Da Silva.
At the other end, Halil Altintop shot wide of the left post and Croatia midfielder Ivan Rakitic sent a right-footed shot from the right side of the area towards the far bottom corner, but Miller dived to save.
Farfan, who has failed to live up to expectations since his move from PSV Eindhoven last summer, made the points safe with the second in the 80th minute.
The Peruvian received a pass from Kuranyi and slide the ball past Miller from six yards to kill off Karlsruhe.