Werder Bremen and Schalke both recorded wins in the Bundesliga on Wednesday.
The duo are locked together at the top of the table and victories on Wednesday took them both onto 42 points.
Werder claimed a 2-0 victory at Bayer Leverkusen, with their goals coming from Miroslav Klose and Hugo Almeida.
Schalke responded with a win of their own, but they were made to fight hard by Alemannia Aachen.
Vedad Ibisevic fired Aachen ahead on 17 minutes, but the lead was short lived as Rafinha netted a penalty on 23 minutes.
Schalke found it tough to break down the visitors after the break, but Moses Sichone put through his own net 16 minutes from time to hand victory to the title chasers.
Hannover went some way to easing their relegation fears with a 5-0 drubbing of European hopefuls Hertha Berlin.
Vinicius Bergantin netted twice before the break to put Hannover in control and a third from Frank Fahrenhorst seconds before half-time took the game beyond Hertha.
Hannover cruised through the second-half and goals from Jan Rosenthal and Altin Lala capped a fine evening's work for the northerners.
Leon Andreasen's penalty just past the hour handed Mainz a priceless 1-0 win over Borussia Dortmund.
The victory combined with Hamburg's 1-1 draw with Energie Cottbus hauled Mainz off the foot of the table.
Those who turned up late at Hamburg will be rueing their shoddy timekeeping as the home side led on four minutes through Juan Pablo Sorin, but Energie clinched a point thanks to Sergei Radu's effort on nine minutes.