RSL continued their winning streak in the most dominant fashion, easily accounting for Swan Hill.
The Blues chased down 135 without losing a wicket, thanks largely to skipper Ben Hallam, who finished the day unbeaten on 53, and Paul Munro, who retired not out on 57.
After electing to bat, Swan Hill were looking good at 1/91, helped by a 77-run second-wicket partnership by Lachlan Edwards (59) and Ammar Khalid (24).
The introduction of in-form leg spinner Oscar Hier changed the game, claiming both members of the partnership in the space of eight balls, triggering a disastrous collapse.
Swan Hill lost their last nine wickets for just 44 runs as Hier claimed a third consecutive four-wicket haul to start the season, taking 4/29 from eight overs.
James Downing (2/12) and Brenton Caldwell (1/14) also impressed
RSL sit atop the ladder as the only unbeaten side after four rounds, while Swan Hill and Ultima-TUF are the only teams yet to win a match.
