Career
A versatile player, Kienast played predominantly in midfield for Rapid, but was also employed in defence or in attack. After his 14 seasons at Rapid, he moved to city rivals Favoritner Air Corps. He finished his career with minor sides Süßenbrunn and SG FavAC Simmering. In 1993/1994 he became assistant-coach at Rapid.
He skippered Rapid from 1989 through 1992 and was voted Austria Fan"s Football player of the Year in 1986.
Kienast earned 13 caps for the Nationalmannschaft between 1983 and 1987, scoring 3 goals. In 1986 he scored two of those in a sensational 4–1 defeat of West Germany.