Watsonians beat Heriot's Rugby 32-17 to replace them at the top of the new Super6 table.
On the second weekend of the competition, Ayrshire Bulls recovered from their opening day loss to beat Boroughmuir Bears 32-27.
Stirling County and Southern Knights drew 24-24.
The six sides will play 20 competitive matches each season made up of 10 Super6 fixtures, plus playo-ffs and cross-border matches.
The competition is designed to "bridge the gap between the domestic and the professional game" say organisers.