Born in Hedehusene, he started playing football with a local team. He moved to Køge Boldklub at the age of 20, where he played for a year, before moving abroad to play for American team Detroit Cougars. He joined Dutch club Sparta Rotterdam, for whom he made his debut for the Denmark national team in June 1971. He moved to Sparta's inner-city rivals Feyenoord Rotterdam, and was eventually dropped from the Danish national team in November 1972. He was a part of the Feyenoord team which won the 1974 UEFA Cup, but despite playing for a successful team, he was not recalled for the Danish national team. Partly because the national team had prolific attacking players like Henning Jensen, Ulrik le Fevre, Per Røntved and not least Allan Simonsen. And partly because Kristensen had trouble in getting the time off to travel home to Denmark to play for the national team.
He moved back to Denmark to play for Køge again, and was recalled for the Danish national team in August 1976. He moved abroad once more, to play for German team Hertha BSC in September 1976. With Hertha, he finished in third place of the 1976 German Bundesliga championship and reached the 1977 German Cup final. In 1978, he returned to Denmark, to play for Næstved IF. At the end of his Danish career, he moved to the United States to play indoor soccer, playing for Wichita Wings and the Kansas City Comets.