Hamburg - Werder Bremen and SV Hamburg were held to draws on Sunday, leaving Bayer Leverkusen three points clear at the top of the Bundesliga. SV Hamburg conceded a late penalty in a 2-2 draw at Hanover, while Bremen were pegged 1-1 by visiting Borussia Dortmund.
At the bottom of the table, basement club Hertha Berlin slipped to a 1-0 defeat at home to fellow strugglers Cologne.
Leverkusen, who thrashed Eintracht Frankfurt 4-0 on Friday, top the table on 26 points and are now three clear of Bremen and Hamburg.
Schalke 04, who drew 1-1 at Bayern Munich on Saturday remain fourth, a further point behind.
Midfielder Mesut Ozil gave Bremen a 36th-minute lead over Dortmund with a first-time shot after Aaron Hunt was given time to cross from the right.
Mid-table Dortmund levelled eight minutes after the break when goalkeeper Tim Wiese could only parry a Nelson Valdez shot and Argentina striker Lucas Barrios swooped to poke the ball over the line for his sixth goal in as many games.
Marcell Jansen and Eljero Elia were on target for Hamburg in the first half either side of a header by Hanover's Didier Ya Konan in the northern German derby.
But Jiri Stajner converted a penalty two minutes from time after he was adjudged to have been blocked in the box by Tomas Rincon.
Hamburg players protested that rather than a foul on Stajner the striker had deliberately run into Rincon before falling.
"It wasn't a penalty. I just stood there and he ran into me," Rincon said.
Hamburg coach Bruno Labbadia said. "I am really annoyed, also for the team who have been unfairly treated."
In Berlin, Hertha's woes continued when Milivoje Novakovic headed in a Lukas Podiolski free-kick 11 minutes from time. It was a 10th league defeat in 12 games for Hertha who are four points adrift of Bochum, while Cologne move up to 13th.
