A bonus point allowed the injury-plagued Bulls to go top of the South African conference as the Pretoria-based franchise scored a fifth win in eight matches.
An early try from centre Jan Serfontein, who turned 20 last week, spoilt the homecoming for Southern Kings, returning to Port Elizabeth after a surprisingly successful run of results in Australasia over the past month.
A crowd of almost 45,000 at the Nelson Mandela Bay Stadium was hopeful the Kings could continue their unexpectedly proficient start to a debut Super Rugby season but was silenced by the early dominance of the visitors.
The opening try, after just five minutes, was followed by a second in the 23rd minute as the Bulls ran from deep in their half in an uncharacteristic free-flowing surge which ended with scrumhalf Jano Vermaak sliding over the wet pitch to score.
Both tries were converted by fly-half Morne Steyne, who also added a penalty and drop goal as the Bulls dominated in all phases, particularly the driving mauls and the kicking game, to go into the break leading 20-0.
They lost their momentum after the interval and the second half went scoreless until the final four minutes when the Bulls scored two more tries to take a potentially important bonus point.
Substitute Jacques Potgieter scored after ripping the ball and powering over after several phases of forward aggression as the visitors found a second wind in the closing stages.
With the last play of the game, wing Akona Ndungane sprinted over to secure an extra point after being set up by Potgieter. Replacement fly-half Louis Fouche added the conversions for both tries.
Kings are now second from bottom with 15 points from their eight matches, which have produced two wins and a draw.
Australia's ACT Brumbies top the table with 35 points, while New Zealand's Auckland Blues are second with 31 and the Bulls third with 28.