Having opened the defence of their title with a convincing victory over Hamburg last weekend, Dortmund were unable to build on that at the Rhein-Neckar-Arena, succumbing to Sejad Salihovic's early goal.

A last-gasp goal from Luiz Gustavo, meanwhile, earned Bayern three points with virtually the last kick of the game after Wolfsburg had had a legitimate goal from Patrick Helmes disallowed in the first half at the VW-Arena.

Bayern had lost their opener at home to Borussia Monchengladbach last weekend, and Lucien Favre's side looked to be heading for another victory today when Filip Daems put them ahead from the penalty spot midway through the second half in the late kick-off against Stuttgart.

But the lead lasted just four minutes before Cacau made it 1-1. It got worse for Gladbach 10 minutes from time when defender Roel Brouwers was sent off, but Stuttgart could not make the most of their extra man.

At the top, Mainz and Hannover both maintained their perfect starts to the campaign with 2-1 away wins.

Mainz's hopes of repeating their stunning seven-match winning start to last season remained intact after they made it two wins from two this term at Freiburg.

All the goals came in the second half with Marcel Risse and Eric Choupo-Moting putting Mainz 2-0 up before Freiburg netted a stoppage-time consolation through Papiss Demba Cisse.

Hannover warmed up for their Europa League tie against Sevilla next week with victory at Nurnberg.

Mirko Slomka's side forged ahead after a quarter of an hour through Mohammed Abdellaoue and they doubled their advantage when Konstantin Rausch scored from the penalty spot following a foul on Abdellaoue by Nurnberg goalkeeper Raphael Schafer.

The home side pulled one back through Tomas Pekhart after 55 minutes but Hannover held on to make it two wins from two this season to build on their impressive fourth-placed finish last term.

Elsewhere, four goals in 17 minutes and a hat-trick from Holland striker Klaas Jan Huntelaar secured an emphatic 5-1 win for Schalke over Cologne at the Veltins Arena.

Last season's Champions League semi-finalists fell behind to a Lukas Podolski strike but recovered well to claim all three points as goals from Lewis Holtby and Raul, as well as Huntelaar's treble, gave them their first Bundesliga win of the season.

Hertha Berlin equalised two minutes before the end of each half to deny Hamburg a win and secure a 2-2 draw - their first point since returning to the Bundesliga.

Mladen Petric opened the scoring from the spot for the hosts after 25 minutes, but Tunay Torun levelled just before the break.

Son Heung-min restored the home side's advantage just before the hour mark but Andre Mijatovic struck from a corner to salvage a point for the capital club, who also hit the woodwork twice.