In 1968, Danielsson signed on to play professionally with AFC Ajax and he became a large part of the club's third straight league title.

[2] Danielsson also played in the 1969 European Cup Final against fellow Swede Kurt Hamrin's AC Milan, losing 4–1.

Danielsson scored several important goals both in the Eredivisie and the European Cups, but after a little more than a year returned to Helsingborg, playing in the lower Swedish divisions.

In 1973, he swapped clubs to IFK Norrköping where he spent another year in the highest Swedish division before ending his career where it started, with Ifö/Bromölla IF.

[2] Danielsson made his debut for the Sweden national team during his time in Ifö/Bromölla IF who then played in the Swedish second division.