[1][2] Jensen came to prominence in 1997 when he won the 1997 Speedway Under-21 World Championship.

[6] In 2005, he joined Peterborough Panthers and Oxford Cheetahs and won the 2005 Individual European Championship.

He averaged 8.76 as the team topped the regular season table and then won the play offs.

[8] Previously known as Jesper B. Jensen, in March 2008 he changed his last name to that of his wife Rikke Monberg.

[9][10] He continued to ride for various clubs in Britain and Poland until he retired after the 2015 season.