Serhou Guirassy headed a brace and Julian Ryerson had three assists as Borussia Dortmund defeated Mainz 4-0 on Friday to keep the pressure on Bundesliga leaders Bayern Munich with a sixth straight victory.
Guirassy nodded Dortmund ahead 10 minutes into the game off Ryerson free-kick from the right.
Five minutes later another Ryerson cross found Maximilian Beier at the far post, and his header went in off the arm of Mainz goalkeeper Daniel Batz for 2-0.
Mainz' Silas aimed inches wide and team-mate Silvan Widmer was ruled offside when he found the net, but Mainz were 3-0 down in the 42nd when a corner-kick from Ryerson was nodded home by Guirassy. An own goal from Dominik Kohr, in the wake of another Ryerson corner, wrapped up matters in the 84th.
Striker Guirassy has five goals from the last three games after managing only six in the previous 19.
Dortmund, who had chances for more goals in the second half, moved within three points of Bayern, who can restore a six-point advantage with victory at lowly Werder Bremen on Saturday. Dortmund host Bayern in a fortnight.
Mainz are 14th, having won their previous three matches to leave the danger zone.
The victory will also boost Dortmund for their Champions League play-off tie with Atalanta which starts next week.