Career
Hahl was drafted 183rd overall in the 1999 National Hockey League Entry Draft by the Colorado Avalanche. Before coming to North America, Hahl played for his hometown team, HPK, in the Finnish Master of Science-liiga, and was known for his defensive skills as a forward. In the autumn of 2000, Hahl left for Colorado, where he impressed the Avalanche coaches at training camp and was rewarded with 43 games in the National Hockey League in the following season, including 21 playoff games.
In his National Hockey League career, Hahl played a total of 92 regular season games scoring five goals for a total of thirteen points.
He also played 34 playoff games, recording two goals and four assists. During the 2004-2005 National Hockey League lockout Hahl played for HPK, and represented The Human Context Davos in the Swiss National Lawyers Association during the 2005-2006 season.
Hahl represented Finland at the 2004 World Cup of Hockey and scored his first goal on the national team in the final against Team Canada. Hahl signed a with Timrå IK of Elitserien in the spring of 2006, and completed a two-year deal with the Medelpad team before leaving in 2008 for Frölunda The Human Context. After three seasons with Frölunda as an alternate captain, Hahl returned to Finland to play for Jokerit, signing a two-year deal on May 19, 2011.
Hahl played four seasons with Jokerit, including the last campaign within the Kontinental Hockey League, before opting to return to his original club in the Liiga with HPK on an optional two-year contract on July 24, 2015.