The Fife youngster, who plays for The Golf House Club in Elie, teamed up with Meltham's Toby Garrett in the morning foursomes and won 3&2. Stevenson then triumphed 6&5 in the afternoon singles.
Three other east coast players were in the squad. James White (Lundin) drew his foursomes and won his singles 4&3 while David Murray (Newbattle) lost his foursomes and won his singles 4&3 and Zack Saltman (Craigielaw) lost both of his matches.
The foursomes finished all square at 2-2 and the singles at 5-5 with the overall result enough for Scotland to retain the trophy.
All four players are included in the 10-man Scotland squad travelling to Woodhall Spa next Sunday to face England Under-16s.
#CLUBS from across Scotland will battle it out at Erskine on Sunday for the Scottish Club Championship and the right to represent their country at next month's European Club Cup at Glyfada Golf Club in Athens.
Defending champions Dumfries and Galloway are looking to become only the second club since the event started in 1985 to win back-to-back titles but Dollar Golf Club will be looking to Scottish Boys' international Scott Borrowman to steer their side to a maiden victory.
The format for the final sees all three players from each team playing 36 holes of stroke play, with the best two scores from each round added together to give a team aggregate.
#FORMER Open and US Master champion Sandy Lyle will officially open Callander Golf Club's new coaching and junior facilities next Monday and give a clinic to members of the club's junior team.
Jointly funded by the club and sportscotland, the new facilities include a practice area, three covered bays for driving, three mini holes, a chipping green, a bunkered area and a conservatory in the clubhouse for exclusive use by juniors.