Hamburg  - The new year has not been kind so far to German football giants Bayern Munich and Werder Bremen.

Champions Bayern slumped at home to Cologne on Saturday in their third defeat in four games since the Bundesliga winter break.

Werder meanwhile went down to a last-minute goal at lowly Energie Cottbus and have just one point in four games since the season resumed at the end of last month.

However on a day of thrills and spills in the Bundesliga, Bayern's unexpected defeat was again not punished by immediate rivals.

Hertha Berlin led at Wolfsburg but lost 2-1, while Hoffenheim missed a penalty in stoppage time in an entertaining 3-3 draw at VfB Stuttgart.

It put Hoffenheim on top on goal difference, sharing 40 points with Hertha, with Bayern two points behind ahead of Sunday's game between Bayer Leverkusen and SV Hamburg.

While Bayern remain very much in contention in the title race, Werder, champions in 2004 and for so long Bayern's chief rivals, are on the slide.

Both now face a crucial week with Bayern at Sporting Lisbon in the Champions League on Wednesday and Werder visiting AC Milan for survival in the UEFA Cup on Thursday.

And then, on Sunday, the two teams meet in Bremen in a Bundesliga encounter which both will now be even more desperate to win.

Bayern were licking their wounds Sunday after their surprise slip-up at home to Cologne, who hit Juergen Klinsmann's side twice on the break in the first half through Fabrice Ehret and Daniel Brosinski, and then held on despite a late Daniel van Buyten goal.

"We're disappointed. A win would have put us top of the table. But we've also been lucky, as our rivals are still only just ahead of us," chairman Karl-Heinz Rummenigge acknowledged.

"We've lost two in a row, and we need to get out of this rut very quickly, starting with Wednesday's game in Lisbon," he added.

Klinsmann brought back Lukas Podolski for the injured Luca Toni but the Germany striker - who is heading to Cologne at the end of the season - could not impress and was replaced at half-time by US striker Landon Donovan.

"Not much went right for us today. We've had the opening goal (from Miroslav Klose) disallowed, then we went behind and lost our cool," Klinsmann said.

"This is a really irritating defeat. Yet again, we've missed a chance to go top of the table. That's very bitter. Put simply, it was a poor performance."

Bremen meanwhile had been hoping an encouraging display in a 1-1 home draw with AC Milan in midweek would translate into Bundesliga points, but it was not to be at Cottbus.

Playmaker Diego was well shackled and despite taking the lead through Hugo Almeida, Bremen went down to goals from Ivica Iliev and Dimitar Rangelov in the last minute.

"We only have ourselves to blame," coach Thomas Schaaf said.

"Again we have allowed our opponents too many chances and again we have put a lot of effort into a game and got too little out of it."

The defeat leaves Werder 11th with hopes of European football next season fading fast. Although still nine points off the relegation zone, a defeat at home to Bayern would leave the team in trouble.

So far it's the worst season since coach Schaaf and sports director Thomas Allofs took the reins 10 years ago.

Hertha Berlin meanwhile lost their top spot in a 2-1 defeat at Wolfsburg which left them fuming after Edin Dzeko's winner six minutes from time was allowed although the striker appeared to push Josip Simunic as he headed the ball over the line.

"It's hard for us to take but referees are only human and make mistakes. I only hope something like that doesn't happen again," Hertha's Swiss coach Lucien Favre said.

Hoffenheim remained upbeat despite squandering a stoppage-time penalty at Stuttgart. They took the lead, then twice came from behind to draw 3-3 - thanks to a hat-trick from Senegal striker Demba Ba - before Sejad Salihovic blasted over the bar from the spot. dpa