The result keeps fifth-place Frankfurt on course for Europa League qualification. Traveling Frankfurt fans stayed away for the whole of the first half in protest, then took their places for the second after setting off pyrotechnics to announce their arrival.
They were just in time to see Goncalo Paciencia open the scoring with a header to Jonathan de Guzman's looped cross in the 48th. The home fans also made their opposition to Monday night games known, calling for "fan-oriented kick off times" in banners around the ground.
Frankfurt's Makoto Hasebe played despite a broken nose. The Japan defender wore a protective mask but discarded it during the first half.
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