Bayer Leverkusen edged out another win ahead of their Europa League meeting with Celtic next week.
The Rhineland side hosted Mainz at the BayArena in good form with four wins in their last five games, including victory against Ferencvaros in Group D on the same night Real Betis saw off Ange Postecoglou's Hoops.
But the visitors had been flying themselves with Mainz coming off their best Bundesliga start in 10 years.
Former Parkhead kid Jeremie Frimpong started once again in the top flight clash and he looks likely to do so in Glasgow having impressed so far this term.
Leverkusen had the ball in the net midway through the first half but Scotland's Euro 2020 tormentor Patrik Schick was foiled by the offside flag.
Wunderkind Florian Wirtz then sent a chance just wide of the Mainz goal and despite dominating the ball in the first 45 minutes the home side went in goalless at the break.
But the young man – who Germany legend Rudi Voller claims will eclipse Kai Havertz such is his promise – couldn't be kept down for long.
Frimpong helped him out with a neat one-two and Wirtz was capable of providing the finish.
He becomes the youngest ever player to score 10 Bundesliga goals at 18 years and 145 days, breaking the record previously held by Lukas Podolski.
Substitute Amine Adli then seemed to add a second but again the goal was chopped off for offside, this time through the medium of VAR.
But Leverkusen saw out the match to rise up to second in the German top flight.
