Leverkusen remain in 1/3 place in the table with 41 factors, eleven at the back of leaders Bayern Munich and 7 clear of Leipzig who currently occupy the final qualifying spot for next season's Champions League however have a recreation in hand.
Leverkusen opened the scoring inside the thirty fifth minute via Czech striker Patrik Schick who now has 20 league dreams for the season.
Schick, but, turned into later compelled off the pitch with an damage on the start of the second half of.
Aaron Martin levelled for Mainz quickly before the hour mark however Lucas Alario restored Leverkusen's gain in the 74th minute after being installation by means of Moussa Diaby.
Mainz refused to give up and levelled for the second time in the 84th minute through Dutchman Jean-Paul Boetius with Denmark's Marcus Ingvartsen hitting the shock winner with two mins left.
