Hamburg  - Werder Bremen's outside hopes of challenging Bayern Munich for the Bundesliga title were dented in a 3-3 draw at Karlsruhe Saturday.

Schalke 04 meanwhile earned a 1-0 win at off-form SV Hamburg, but Bayern are virtually assured of the title, as they can move to within a point of the title with a win against visiting VfB Stuttgart on Sunday.

Mathematically both Bremen and Schalke can still overtake Bayern, but a victory against Stuttgart will all but give Ottmar Hitzfeld's side the championship.

Bayern would then be 12 points clear with four matches remaining and with a goal difference which is 17 better than Bremen's and 21 better than Schalke's.

Bremen's title aspirations stayed alive thanks to a a goal four minutes from time from Boubacar Sanogo to earn a point at Karlsruhe.

Karlsruhe's Sebastian Freis scored twice before Edmond Kapllani put the home side 3-2 up in the 69th minute.

Bremen had come from behind to a 15th-minute Freis goal, with Brazilian midfielder Diego equalizing in the 23rd and Mesut Ozil netting six minutes later.

Freis finished off a solo run from his own half to level in the 59th and Bremen were caught open at the back for Kapllani to score 10 minutes later, but Sanogo rescued a point with a close-range goal.

The result leaves Bremen second, level on 54 points with Schalke, who got off to a perfect start at Hamburg when an unmarked Kevin Kuranyi nodded in a cross from Albert Sreit after just two minutes.

SV Hamburg stay fourth on 48 points but see their hopes of European football next year beginning to fade after six games without a win. They could drop to sixth depending on Sunday's games, with Bayer Leverkusen also in action at home to Wolfsburg.

The battle to avoid relegation remained tense, with Energie Cottbus coming from behind with 10 men to beat fellow strugglers Hansa Rostock 2-1 with an injury time goal.

Duisburg took the lead at Bochum thanks to a brilliant 30-metre free-kick from Claudiu Niculescu, but the home side hit back with an 84th-minute header from Stanislav Sestak.

Arminia Bielefeld meanwhile came from 2-0 down at Nuremberg to earn a 2-2 draw.

The results leave Duisburg bottom on 26 points, one adrift of Hansa Rostock and Nuremberg.

Hanover drew 2-2 with Hertha Berlin, while on Friday evening, mid- table sides Eintracht Frankfurt and Borussia Dortmund finished 1-1. (dpa)