At the FIS Nordic World Ski Championships, Hagen won golds in the individual nordic combined (1934, 1935) and silvers in the men's 4 x 10 km and the men's 18 km (both 1935). Hagen's consecutive world championships in nordic combined would not be repeated until fellow Norwegian Bjarte Engen Vik won the event in 1999 and 2001.
At the Holmenkollen ski festival, Hagen won the nordic combined event three times (1932, 1934, and 1935). For his nordic combined successes at the Olympics, Holmenkollen, and World Championships, Hagen earned the Holmenkollen medal in 1934.