Petersen's fourth straight ton sinks Knights
The margin of victory meant Lions pocketed the bonus point to lift themselves into the third spot at the halfway mark in the competition.
Petersen, who made a 128-ball 134, found support from Neil McKenzie (56), Dwaine Pretorious (50 off 22 balls) and Stephen Cook (42) as Lions posted an imposing 317 for 6 in 50 overs after being sent in to bat. The Knights' chase fizzled out early as they lost their top five inside 100 runs, with the side eventually bowled out for 133 in 34.5 overs.
Eddie Leie, the legspinner who was recently part of the T20I series in India, returned figures of 5 for 30, while Pretorious also contributed with the ball with three scalps.
Warriors beat Cobras by five wickets in Cape Town to cement their second spot in the points standings. Sisanda Magala, the pacer, picked five wickets to restrict Cobras to 250 for 9. That they got there was courtesy a 98-ball 77 from captain Justin Ontong.
Warriors were driven by Colin Ingram, who top-scored with 77 to help the team march ahead of the asking rate. Although they lost two quick wickets to leave the team at 174 for 5, the momentum provided by Ingram helped them prevail. Christiaan Jonker (44 not out) and Colin Ackermann (35 not out) shared an unbroken sixth-wicket stand of 79 to see the Warriors home with seven balls to spare.