The Lions, who were runners-up in the competition last year, won for a fourth time in five games this season as teenage Congo-born winger Madosh Tambwe grabbed two tries and the Springbok trio of Malcolm Marx, Elton Jantjies and Jaco Kriel also scored before halftime in Port Elizabeth.
But they turned in a strangely disjointed second-half showing and waited until four minutes from the end to add more points when Harold Vorster went over to ensure the bonus point.
The Kings, who never looked capable of ending their unwanted record of never beating a fellow South African franchise, scored inside the opening minute through Andisa Ntsila and saw debutant Yaw Penxe and fullback Malcolm Jaer also cross over for tries.
The early score for the home team came as Ntsila charged down a clearance to go over after just 50 seconds but a horror error by the Kings just two minutes later, when a cut out pass on their own line was intercepted by 19-year-old Tambwe, brought parity.
Marx and Jantjies then scored in quick succession to extend the Lions’ lead to 21-7 inside the opening 15 minutes before Ntsila’s break from inside his own 22 set up 19-year-old Penxe for a debut score.
But Tambwe, with another easy cross over, and Kriel added to the Lions’ try tally to make it a convincing 35-12 at half-time.
The second half was just three minutes old when Jaer reduced the deficit as he stepped into a narrow gap to score after which the Lions seemed to loose momentum.
But with four minutes left, they broke out from a line out for Kriel to set up Vorster for a potentially important bonus point.
STORMERS REMAIN UNBEATEN
The Stormers made an astute tactical change midway through the first half to rally from a 14-point deficit and maintain their unbeaten start to the season with a 44-31 victory over the winless Sunwolves in Singapore on Saturday.
The Sunwolves ran in four tries with some exhilarating expansive rugby but the Cape Town-based side countered with a pick-and-go approach to utilise their forward strength and went ahead for good on the hour when Dewaldt Duvenage touched down.
EW Viljoen, Rynhardt Elstadt, Wilco Louw, Mbongeni Mbonambi and Bjorn Basson also scored tries for the Stormers, while Robert du Preez kicked two penalties and four conversions in the fourth straight win of the season for the visitors.
Derek Carpenter scored twice for the Japan-based Sunwolves, with additional tries coming from Shota Emi and Liaki Moli. Jumpei Ogura kicked four conversions and one penalty as his side lost for the fifth consecutive time.
VAN WYK SHINES FOR SHARKS
Winger Kobus van Wyk crossed for two tries and teenager Curwin Bosch made a seamless transition to flyhalf as he kicked 18 points to hand the Sharks a hardfought 38-30 away win at the Free State Stadium in Bloemfontein, South Africa.
The Sharks also scored tries through Lwazi Mvovo - his 30th in Super Rugby - and substitute Dan du Preez while the home side replied through returning captain Francois Venter, JW Jonker and Raymond Ruhle in the last minute.
The 19-year-old Bosch was playing at flyhalf in place of injured Pat Lambie and enhanced his growing credentials with a commanding kicking performance.