Bundesliga leaders Borussia Dortmund were held to a goalless draw by bottom club Nuremberg in a game overshadowed by a protest over kick-off times.
Half-time arrived in controversial fashion as for the second time home fans threw black tennis balls onto the pitch, protesting against the Monday night fixture.
With Dortmund waiting to take a corner referee Harm Osmers blew the whistle and took the teams off.
Dortmund's English youngster Jadon Sancho was pictured being inadvertently struck by the missiles, on what was a frustrating night for him and his team.
Dortmund, who were missing Chelsea-bound Christian Pulisic with a thigh injury suffered in last week's Champions League defeat to Tottenham, struggled to break down the obdurate home defence inspired by new coach Boris Schommers and goalkeeper Christian Mathenia.
Home skipper Hanno Behrens had a header brilliantly tipped over by Roman Burki and, from the resulting corner, sent an unmarked header over the bar from just outside the six-yard box after Dan-Axel Zagadou misjudged the cross.
Sancho was denied a penalty at the other end, while Mario Gotze was prevented from scoring several times by Mathenia and Axel Witsel's shot was deflected wide by Behrens.
Dortmund still could find no way past the agile Mathenia in the second half, and had what would have been a late winner disallowed when Paco Alcacer was correctly flagged offside before squaring to Jacob Bruun Larsen for a tap-in.
The visitors ended the game just three points ahead of rivals Bayern Munich at the summit.