The towering center back climbed above Chico Flores in the second half to plant a header beyond Michel Vorm and secure three valuable points at the Cardiff City Stadium.
The defender, who spent a season on loan with Swansea, netted just his second Bluebirds goal to seal a historic victory for the hosts as their rivals finished the game with 10 men following Michel Vorm's late dismissal.
Cardiff went into the much-anticipated encounter looking to end a run of three games without a win, while Swansea knew it could move into the top half with maximum points.
The hosts made two changes to the side that drew 0-0 with West Ham as Don Cowie and Craig Bellamy replaced Kim Bo-Kyung and Campbell. Alvaro Vazquez was dropped for Swansea, with manager Michael Laudrup bringing Jonjo Shelvey into the starting XI.
Swansea made the better start to proceedings but saw two promising opportunities wasted as Michu and Jonathan de Guzman both shot hopelessly wide from good areas in the early stages.
The visitors continued to press and forced the first save of the game 10 minutes in, David Marshall keeping out Michu's effort from the edge of the area after the Spain international had evaded the home defence.
Cardiff took 25 minutes to create their first chance, Bellamy's free kick deflecting wide off Leon Britton.
Swansea dictated the game for large periods but it was Cardiff who began the second half the stronger. However, they too showed a similar lack of composure in front of goal when Peter Whittingham sliced Bellamy's lay-off well wide four minutes into the half.
The deadlock was finally broken just after the hour mark, though, Caulker rising to head Bellamy's corner past a stranded Vorm.
Laudrup threw substitute Wilfried Bony into the fray immediately after falling behind and the Ivory Coast international almost had an instant impact as he prodded wide from point-blank range.
De Guzman and Alejandro Pozuelo also went close in the closing stages for Swansea but any hopes they had of earning a point were virtually ended when Vorm was dismissed after bringing down Campbell after the former Hull City striker had broken through on goal.