Second-half strikes from Shinji Okazaki and a Matthias Ginter own goal were enough to give Mainz a 2-0 win over Borussia Dortmund.
Mainz were refreshed after a week in which Kasper Hjulmand got his first win as the Carnival club's boss. A thoroughly impressive one too, 3-1 against Hertha Berlin, meant that Shinji Okazaki became the highest ever Japanese goal-scorer in Germany. Jonas Hofmann retained his starting place against his parent club, Petar Sliskovic and Nikolce Noveski remained the only two long term absentees, as Hjulmand named just one change from the triumph in Berlin. Christoph Moritz came in for an injured Ja-Cheol Koo.
Ilkay Gündogan, Marco Reus, Oliver Kirch, Nuri Sahin, Ji Dong-Won, Mats Hummels and Jakub Blaszczykowski played no part in Mainz, as Borussia Dortmund's horrendous injury list continued to worry fans of the club. However, the 2-0 win over Arsenal was almost the perfect game for BVB and showed they could perform even with several first team players out. Plenty of changes were made from that win: Marcel Schmelzer, Sebastian Kehl, Henrikh Mkhitaryan and Ciro Immobile all dropped out, as Lukas Piszczek, Milos Jojic, Shinji Kagawa and Adrian Ramos returning to the starting line-up.
The best chance in the opening stages fell to Lukas Piszczek, who collected a fantastic diagonal pass before having his shot blocked by a sliding Junior Diaz. Soon after Shinji Kagawa broke away from the attentions of Mainz' midfield and he off-loaded to Pierre-Emerick Aubameyang. His cross found an unmarked Adrian Ramos, but for the Columbian to inexplicably put his header wide.
Jonas Hofmann very nearly found the break-through for Mainz. Drifiting past players with ease, he went on a mazy run before shooting low into the grateful Roman Weidenfeller's arms. In truth, the pitch was causing more problems than the hosts for BVB. Constantly cutting up: Weidenfeller, Piszczek and Kagawa were all to fall foul of the turf at the Coface Arena.
The Dortmund custodian had to be extremely alert to keep out an Okazaki toe-poke, in the first real chance of the game. The Japanese forward met a long throw and the 34-year-old got down expertly to save, just before Hofmann tried his luck from range and drew another stop from the BVB 'keeper. Dortmund responded immediately with Piszczek finding Ramos, who turned the Pole's cross onto the post as Mainz' hard work was nearly undone.
The second half began with Borussia Dortmund on top. Junior Diaz was forced into two fine blocks, the stop from Ramos' clear shot on goal was particularly impressive. Though it was Mainz that would take the lead. Loris Karius' long kick up field was straight to Jairo, the substitute controlled it well and found Christoph Moritz. The pair exchanged passes with Daniel Brosinski on the right, before the Spaniard crossed for Shinji Okazaki to tap past Weidenfeller.
Karius was soon called into action again, this time to make a vital stop. Ciro Immobile, just brought on, stepped up to take a penalty after handball was given in the Mainz area. The Italian's penalty was poor and the Mainz' stopper duly obliged in keeping out the weak effort to his right. Almost immediately, the hosts had a second.
Jairo was the man who played the killer pass, as the Carnival club completed their smash and grab.The Spaniard played the ball across goal to find Hofmann, but before he could reach it Matthias Ginter poked it past everyone and into an empty net. There was just time for Henrikh Mkhitaryan to smash the post, it was clear it was not the visitors day.
Dortmund's poor finishing came back to bite them in the backside once more, with Adrian Ramos and Ciro Immobile wasting enough chances between themselves to win the game. Mainz and Kasper Hujlmand will be over-joyed after exits from both cups. Top of the league and still unbeaten, after drab preformances before the Bundesliga started, is a quite fantastic turnaround. They sit top of the league along with Paderborn, Hoffenheim and Bayern Munich after four games, while BVB lie eighth.