Bundesliga leading scorer Robert Lewandowski grabbed an early goal to give leaders Bayern Munich a 1-0 victory at Cologne that sent them eight points clear at the top of the table with seven matches left in the season.
Bayern, on track for a treble of titles after advancing to the Champions League quarter-finals this week, are on 69 points, with second-placed Borussia Dortmund in action against Augsburg on Sunday.
Poland forward Lewandowski notched his 25th goal of the campaign with a well-placed shot in the 10th minute and Bayern were rarely threatened by the hosts in a one-sided game in which the visitors had more than 70 percent possession.
Hertha Berlin edged past Ingolstadt 2-1 to remain on course for a sensational third-place finish, opening up a four-point gap over Schalke, who are fourth.
Andre Schuerrle's last-gasp goal rescued a 1-1 draw for VfL Wolfsburg, who also reached the Champions League last eight, against Darmstadt 98 and they remained in eighth place.