Nouma finished off a good passing move for the first goal. The second was a tap-in for Horvath from about a yard after some good work by Dorrans on the byeline to get it into the danger area.
Stanic played the full ninety - partnering Strong at centre-half in the first half before switching to a more accustomed left-back role after the interval.
Second place is in the bag for the reserves with one game (v Hearts) remaining.
Livi: Fleming, Boyd, Geggan (Miller 45), Easton (Dorrans 45), Strong, Stanic, Kriston, Brittain, Nouma (Scott 65), Horvath, Snodgrass.