Ireland wingers Tommy Bowe and Andrew Trimble scored tries for Ulster in Friday night's 23-10 pre-season friendly defeat by Edinburgh.
The pair were left out of Saturday's World Cup warm-up against Wales but they made an impact at Goldenacre.
Bowe scored the games's opening try although the Scots went in 17-5 ahead at half-time after tries from Magnus Bradbury and Otulea Katoa.
Trimble touched down before Jack Cuthbert fired over two late penalties.
Ulster fly-half Ian Humpreys suffered a hamstring injury in the warm-up and was replaced by Sam Windsor.
Irish coach Joe Schmidt said on Thursday that Trimble, who is recovering from a foot problem, would get more game time with Ulster than in the match with Wales.
Ulster: C Gilroy, T Bowe, L Marshall, S McCloskey, A Trimble, S Windsor, P Marshall; A Warwick, R Herring (capt) W Herbst, D Tuohy, F Van der Merwe, C Ross, S Reidy, R Diack.
Replacements: P Jackson, R Murphy, R Lutton, P Browne, W Faloon, D Shanahan, S Arnold, L Ludik, P Nelson, C Joyce.