( CNN ) -- Japan winger Shinji Kagawa was on target for Borussia Dortmund in a 1-0 win over Bayer Leverkusen on Saturday to keep the reigning champions at the top of the Bundesliga . The Japanese winger fired home from a tight angle on the stroke of halftime to bag his fourth goal in as many games . The win sees Dortmund maintain their two-point lead over Bayern Munich who enjoyed a comfortable 2-0 victory over Kaiserslautern thanks to goals from Mario Gomez in the sixth minute and Thomas Meuller after 30 minutes . Mid-table Stuttgart thrashed 10-man Hertha Berlin 5-0 . Austria striker Martin Harnik scored a first half brace after Vedad Ibisevic had given Stuttgart the lead , with Shinji Okazaki also on target in the first half . The half also saw Hertha 's Andreas Ottl sent off for a foul on Hungary midfielder Tamas Hajnal . Georgian defender Leven Kobiashvili compounded 15th-placed Hertha 's miserable afternoon with an own goal in the 59th minute . Hoffenheim 's new coach Markus Babbel , who replaced recently sacked Holger Stanislawski , picked up his first point with a 1-1 draw at Werder Bremen . Bremen 's Austria striker Marko Arnautovic denied Hoffenheim victory with an injury time equalizer after Danish defender Jannik Vestergaard had given the visitors a fourth-minute lead . Hannover salvaged a point in their game at Mainz thanks to an injury-time goal from but Polish striker Artur Sobiech after Mohamed Zidan had put the home side ahead in the seventh minute of the game .
Borussia Dortmund maintain two-point lead with a 1-0 win against Bayer Leverkusen . Bayern Munich keep up the pressure with a 2-0 victory over Kaiserslautern .