They move out of the bottom three, at least for a night.
An Alexander Meier goal 10 minutes before half-time was enough to earn the Eagles all three points and take them back above Freiburg thanks to their first home win of the Bundesliga season.
Hertha spent the first half chasing the game and when only improved slightly in the second half, but with the Bundesliga's top goalscorer Adrian Ramos drawing a blank, they were left clinging on to a sixth position they could lose on Sunday.
It was immediately clear that Frankfurt felt they had a point to prove against a side who had hammered them on the opening day of the season.
Nearly six months have passed since that game, and how things have changed.
In spite of their caution, Frankfurt never let Hertha get a glimpse of their goal in the first half, although they were fortunate with the way they took the lead.
A long, hopeful punt forwards from Marco Russ was left by two Berlin players in midfield, and Meier was given a free run on Thomas Kraft's goal.
The club's top goalscorer from the past two seasons did not make any mistake, keeping his composure to beat the Berlin custodian for his fourth goal of the season in only his ninth appearance of an injury-ravaged year.
All of a sudden, it seemed like a weight had been lifted. Berlin, who had held most of the possession without penetrating, found themselves chasing the ball, and chasing the game.
It took the Old Lady over an hour to settle, by which time Frankfurt had raised the barricades in a bid to defend their first win of the season.
Ronny tried his look with a few long-range efforts, but the fact top-scorer Ramos got his first sight of goal after entering the final third of the game said it all.
Ronny kept chipping away, but he was not on a wavelength with his team-mates and fighting a lone mission against what had gradually become 11 Frankfurt players behind the ball.
Their reaction to the final whistle was symptomatic of the relief in the Waldstadion.
Goalkeeper Kevin Trapp fell to his knees for what may only have been a narrow 1-0 win over a side promoted to the top flight last season, but in view of Freiburg's win over Leverkusen, it meant far more.