Bundesliga leaders SV Werder Bremen moved eight points clear at the top of the standings despite being held to a 0-0 draw at home by Hannover 96 on Sunday.
Bremen remain firmly in control with five matches left after second-placed FC Bayern München's 2-0 defeat against BV Borussia Dortmund on Saturday. The leading pair are due to face each other at the Olympiastadion on 8 May, but by then the title could already be Bremen's.
Thomas Schaaf's side dominated the northern German derby but the coach was frustrated by their failure to find the net. "We absolutely wanted three points but we'll have to be satisfied with one," he said. "We tried everything, especially in the second half, but it just didn't work out."
In the day's other game, VfL Bochum 1848 held on to fifth place and stayed on course for a place in the UEFA Cup with a 2-1 victory at 1. FC Köln, which left the bottom club needing at least three wins and a draw from their final five matches to avoid relegation.
Visiting captain Dariusz Wosz opened the scoring for Bochum on the half-hour mark and although Köln responded through striker Lukas Podolski in the 54th minute, 26-year-old Bochum defender Frank Fahrenhorst headed what proved to be the winner ten minutes later.