Finlay Gillies and Jon Welsh went over for tries while Scott Wight kicked four conversions.
Former Warrior Opeta Palepoi grabbed a try for Gala.
Defending champions Ayr went down 20-19 to Heriot's at Goldenacre. EDP hooker Fergus Scott went over for a try for Ayr while Finn Russell and Jerry Yanuyanutawa were second-half replacements for the Millbrae. Kevin Bryce featured for the home team.