With a total appearance in 167 games during his first four years in the club, he was counted on as one of the most regular first team players at the pitch.
[3] In 1985, Claus Nielsen was honoured with the title "best Brøndby player of the year",[4] and he also managed to qualify as the overall topscorer of the Danish league in 1986 and 1987.
[5] The long string of goals from Nielsen, also helped Brøndby to win the Danish championship in 1985 and 1987.
[6] He continued to play well in spring 1988, but as he transferred to Panathinaikos already after the first half of the season, he was not in contention to repeat his win of the Brøndby topscorer title in 1988.
[7] Nielsen played 14 games and scored eight goals for the Denmark national football team from October 1986 to June 1991.