Hamburg ended the amazing run of Mainz in a 1-0 victory through a last-gasp goal on Saturday, snapping Mainz the lead in the Bundesliga and its seven-win streak to start the season.
Mainz slipped to second place on goal difference behind Borussia Dortmund, which won 2-1 at Cologne on Friday to take first place for the first time in seven years.
Paolo Guerrero's score in the 89th minute for Hamburg denied Mainz the chance of clinching an eighth successive win and tying the Bundesliga record for the best season start.
In other matches, striker Mario Gomez scored a hat trick in Bayern Munich's 3-0 home win over Hannover.
Klaas-Jan Huntelaar converted a late penalty to salvage a 2-2 draw for Schalke against bottom-place Stuttgart, Werder Bremen edged Freiburg 2-1, and St. Pauli beat Nuremberg 3-2.
In the late game, Simon Rolfes had two goals and played a role in another as Bayer Leverkusen overcame a two-goal deficit to win 3-2 at Wolfsburg.
Ze Roberto, who had hit the post in the first half for Hamburg, set up Guerrero's goal by breaking free on the left side and slipping a short pass for the Peru striker to drill into the roof of the net.
Marco Caliguiri struck the post for Mainz and Hamburg had a score disallowed when striker Ruud van Nistelrooy was called for a foul before he headed the ball into the net.
Hamburg moved to seven points behind Dortmund and Mainz, which both have 21 points. Dortmund has won its last seven to tie the club record.
Bayern, the defending champion, cut the gap to the top to 10 points despite missing several injured regulars, including striker Miroslav Klose and Ivica Olic.