A self-confessed AIK supporter, Antonelius played for Brommapojkarna, AIK, Coventry City in the Premier League and FC Copenhagen in Denmark. He also had a brief stint with Canadian side Winnipeg during a year in college in North America.
In 2002 he left Coventry to join F.C. Copenhagen, however, he suffered a serious knee injury 1,5 years after joining the club and never played football again. He announced his retirement in September 2003 due to this failure to recover from the injury. He was part of the Swedish squad at Euro 2000 and the 2002 FIFA World Cup.
UEFA Cup Winners' Cup Quarter Final 1997 against Barcelona (1-3, 1-1)
Swedish league Champion 1998, Cup winner 1997 and 1999 with AIK.
Champions League group stage 1999
Danish League Champion 2002/2003 with Copenhagen