Career
Doniņš placed sixth in the javelin throw at the 1969 European Championships in Athens with a throw 79.10 m (259 ft 6 in). At the European Championships later that year in Helsinki he threw 85.30 m (279 ft 10 in) and placed second behind his teammate Jānis Lūsis. Track & Field News ranked Doniņš tenth in the world in 1969 and second in 1971.
He was one of the favorites for the 1972 Summer Olympics in Munich, but suffered a career-ending knee injury in training in February 1972.