Schalke drew 3-3 with Hamburg while Mainz beat Stuttgart 3-2 in Sunday's Bundesliga action.
Klaas-Jan Huntelaar gave Schalke the lead in the second minute, but a Rafael van der Vaart penalty brought Hamburg level 10 minutes later.
An own goal from Timo Hildebrand gave Hamburg the lead in the 24th minute, but Huntelaar's second of the game on the stroke of half time brough the Royal Blues back on terms.
Lasse Sobiech put Hamburg in front for the second time early in the second half, but Adam Szalai salvaged Schalke a point in an entertaining encounter.
Shinji Okazaki got one over his former club with a goal on his Mainz debut, helping to defeat Stuttgart 3-2.
Nicolai Muller put Mainz in front in the 14th minute, but Vedad Ibisevic replied within two minutes for the guests.
Okazaki then equalled his tally for the whole of last season as a Stuttgart player to put Mainz in front again before Muller got his second of the game.
Martin Harnik reduced the arrears once more, but it was too late for Bruno Labbadia's men to find an equaliser.