Hertha Berlin have made an official appeal after losing their play-off to Fortuna Dusseldorf on Tuesday.
Fortuna won the game to claim promotion to the Bundesliga at top-flight Hertha's expense, with the 2-2 draw at home in the second leg giving them a 4-3 aggregate victory.
However, Hertha have protested the decision as a result of the Fortuna fans' pitch invasion shortly before the final whistle. The incident held up play for 20 minutes.
"After analysing the situation, we have reached a clear decision that a regular procedure of the game was no longer possible in these conditions," Hertha's director of sport Michael Preetz said. "We have therefore appointed our solicitor Christoph Schickhardt to officially appeal the result within the necessary deadline."
Following the resumption of play, referee Wolfgang Stark blew the final whistle slightly earlier than scheduled, and Schickhardt feels Hertha have a good chance of having the game replayed.
"In the DFB regulations, it clearly states that a game which takes place in such circumstances must not be given an official result," he said on the club's website. "That necessarily leads to this result being annulled."
Fortuna have cancelled their planned promotion celebrations this weekend.