Freshly-crowned German Cup winners Borussia Dortmund booked a Champions League spot for next season with a comfortable 3-1 victory at Mainz on Sunday that made sure of a top-four finish with a game left in the season.
A curled shot from Raphael Guerreiro in the 22nd minute put the visitors in the driving seat and two minutes before the break Jadon Sancho threaded a ball past two defenders and Marco Reus tapped in from close range to double their lead.
Julian Brandt rounded the keeper in the 80th minute to seal their victory and help lift Dortmund, who beat RB Leipzig on Thursday to win the German Cup, to 61 points and third place with their sixth consecutive league win.
Mainz scored with a stoppage time penalty from Robin Quaison.
Frankfurt, in fifth, are on 57 points with one game left.
The top four teams qualify for the lucrative Champions League group stage, Europe's premier club competition.
Champions Bayern Munich and second-placed RB Leipzig have already booked their spots. VfL Wolfsburg, fourth on 60 points, will punch the last of the four tickets if they earn at least a point against Leipzig later on Sunday.