Kinghorn replaced injured Finn Russell in the starting XV and took his chance with a match-winning performance, though in general there was a lack of creativity and invention from the Scots as winger Duhan van der Merwe also crossed for a score.
Italy defended heroically at times and on a rare foray into the Scotland 22 scored their only try through fullback Tommaso Allan. Trailing by five points, they camped on the Scotland try line for the final few minutes but Scotland broke from their own 22 to complete the win
Scotland will delightin a second top-three Six Nations finish in the last 10 years unless England obtain a immense bonus-point win in Ireland later on Saturday.
Italy finished bottom of the table having lost all five fixtures, though their performances gain been much improved this season.