By Patrick Goss
Last Updated: 01/01/70 1:00am
Werder looked to have been held to a draw, Ivan Klasnic cancelling out a Vaclav Sverkos strike.
However Baumann pounced in injury time to give his side another victory, that extends the gap at the top.
Kaiserslautern took a big step towards safety with a 1-0 win against Cologne - Vratislav Lokvenc scoring the crucial goal.
Bayer Leverkusen were beaten at home by Eintracht Frankfurt. Oliver Neuville had put Bayer back in the game when he cancelled out Ingo Hertzsch's opener, but Ioannis Amanatidis stole the points for the visitors on 77.
Borussia Dortmund impressed with a 4-2 win against Wolfsburg - despite conceding a Martin Petrov penalty.
Niclas Jensen, Jan Koller, Torsten Frings and Lars Ricken gave Dortmund an unassailable lead although Fernendo Baiano did grab a late consolation.
Bernardo Romeo's late leveller earned Hamburg a point against Bochum - who had opened the scoring through Soren Colding.
Hansa Rostock were too strong for Freiburg - earning a 4-1 win.
Antonio Di Salvo, Magnus Arvidsson, Gernot Plassnegger and Razunda Tijkuzu were all on the scoresheet for the home side, whilst Wilfried Sanou scored a consolation for Freiburg.
Finally, Schalke were held at home to 1860 Munich.