Hertha Berlin are tottering on the verge of Bundesliga relegation after a 1-0 home defeat to Hamburger SV in the first leg of their playoff.
Ludovit Reis scored the winner in the 57th with what appeared to be an intended cross from the right which sailed over debutant reserve goalkeeper Oliver Christensen in off the far post.
Hamburg were the better team in the sold-out Olympic Stadium that crammed in 75,500 fans and they are now well-positioned for the return leg at home on Monday in their bid for a Bundesliga return after four years in the second tier.
Coached by former Hamburg playing great Felix Magath, Hertha now face an uphill battle to avoid a first drop in a decade and seventh overall.
Hertha were in the play-off as the third-last Bundesliga finisher after failing to win in their last three games while Hamburg came third in the second tier with five straight wins.
"We saw in the past weeks that something is growing. It was a good first leg," Hamburg board member for sport Jonas Boldt told Sky TV.
"Now we have a home leg. We are in a comfortable position. We have invested a lot and now we want to clinch matters."
Hertha defender Niklas Stark said: "It is only 1-0. Everything is still possible. We wanted to get a result. All that counts now is Monday. We have to stay positive."
Hertha thought they had taken the lead just before half-time from Ishak Belfodil's header but he was ruled offside in the build-up by video review.
Instead it was Hamburg who got the breakthrough from Reis which boosted their morale, and they were closer to a second goal than rattled Hertha to an equalizer in the remaining minutes.
Australian Associated Press
Sign up for our newsletter to stay up to date.