A late goal away in Dresden booked Fortuna Düsseldorf's ticket back to the top flight of German football with two games to spare. The second division league leaders last played in the Bundesliga in the 2012/13 season.
Düsseldorf's 2-1 win away to Dynamo Dresden on Saturday made promotion a mathematical certainty. Coach Friedhelm Funkel's club have 59 points at the top of a fiercely competitive second division, 10 points clear of third place, and are guaranteed one of the two automatic promotion places.
Rouwen Hennings sealed the deal in the last minute of the match. Allowed too much space on the edge of the area, Hennings was able to steady himself and drive a low left-footed shot into the bottom corner.
Florian Neuhaus had given Fortuna an early lead in the opening period, but Dresden substitute Moussa Kone had leveled the score in the 64th minute.
It's the sixth time Fortuna Düsseldorf have won promotion to the Bundesliga, though they've not been in the top flight since the 2012/13 campaign ended in relegation.
Düsseldorf are still in a battle with 1. FC Nürnberg for the second division title. Nürnberg could pull within two points of the leaders with a win in their Monday evening match in Braunschweig.
Düsseldorf will swap places in the top flight with fierce local rivals Cologne. The Billy Goats relegation was confirmed later on the very day that Düsseldorf secured promotion.