The Scots went off to a flying start when Saracens winger Duncan Taylor crossed the white wash inside the first minute for a brilliant solo finish from a loose George Ford’s kick.
Tom Heathcote added the extras and Scotland A were leading 7-0.
Ford responded quickly with a penalty but Heathcote added a penalty of his own to see the visitors lead 10-3 after six minutes.
Neither side could put their game in place and Ford added a penalty to trail 10-6 at the break.
Heathcote added a penalty early in the second half before defending their lines hard.
Ford and the Saxons made it a four-point game with eight minutes to go but were unable to score again and Scotland had their win despite being down to 13-men for the closing minutes.
Man=of-the-match Ryan was joined by fellow-Warriors Sean Kennedy, Tom Ryder, Tim Swinson, Jon Welsh, Alex Dunbar, Gordon Reid and James Eddie.