Two tries from centre Stokkies Hanekom helped the Lions to a 26-19 victory over the Southern Kings in the first leg of South Africa's Super Rugby promotion/relegation playoff in Port Elizabeth.
The two teams are trying to become the fifth South African franchise to qualify for next year's championship.
The Lions are looking to get back in the competition after missing out in 2013.
The Kings, in their maiden Super Rugby campaign, finished bottom with three wins from 16 matches and must win the second leg at Ellis Park on August 3 to avoid dropping out of the championship.
