The second division side's 'Fortuna for Everyone' campaign, a plan to make all tickets for certain home games free, grabbed headlines before the season. The two-time German Cup winners started by making tickets free for three home matches in 2023-24, while pledging to continue the plan if they reached the top division.
Each of the three games were 'sold out', with fans filling Duesseldorf's 52,000-capacity home ground - one of the venues for this summer's Euros. Over the season, league crowds averaged more than 39,000.
The home support made an impact on the pitch. Fortuna came from three goals down to beat rivals Kaiserslautern 4-3 in the first free-ticket game in October.
Although Fortuna lost the second free-ticket game to eventual division champions St Pauli in January, their win in the third fixture against Eintracht Braunschweig in April put them on course for a third-placed finish and a shot at the top division.
'First division and stay there'
Fortuna CEO Alexander Jobst told AFP and other media in an interview in October before the first free match that the plan would supercharge rather than hinder their promotion bid. "Following the old business model would not have given us the chance to become a first-division club," Jobst said, explaining the plan had "more opportunities than risks."
"(The plan) gives us a higher chance to get up to the first division and then to stay there." Tickets for the second leg of the relegation playoff will not be free, but Duesseldorf will have no trouble selling out their stadium. Fortuna's last stint in the top division ended after two years with relegation in the 2019-20 season.
The playoff has come under criticism in Germany because the top-division teams have dominated. Scrapped after German reunification in 1991, the playoff was reintroduced in 2009. There have been 16 playoffs since then, with the second-division side winning promotion just three times.
The last time was in 2019, when Union Berlin triumphed over Stuttgart under the away goals rule, which was abolished in 2021. Although the odds may be against second-division Fortuna, they are one of the three to have won promotion via the playoff, beating Hertha Berlin in 2012.
'Beat a Bundesliga team'
Fortuna striker Christos Tzolis said Tuesday his team would step up. "If we want to become a Bundesliga team, we have to beat a Bundesliga team," Tzolis told the club website. Unlike Bochum, who stumbled towards the end of the season with two wins in their past 12 matches, Fortuna come into the crunch match in good form.
Fortuna's only defeat in their past 15 games in all competitions came against Xabi Alonso's all-conquering Bayer Leverkusen in the semi-finals of the German Cup - hardly an embarrassment, given the Bundesliga champions 51-game unbeaten run.
"Bochum is not in really good shape but they are still a strong and, above all, a physically robust side. These will be two close games. But I'm really positive about what's in front of us."