BERLIN (AFP) - Schalke 04 went top of the Bundesliga on Saturday thanks to a superb header from Germany defender Heiko Westermann to seal a 1-0 win over VfL Bochum to knock Hoffenheim from top place.

The 25-year-old, who was in Germany's Euro 2008 squad, converted a cross from Brazilian team-mate Rafinha on 36 minutes which put the Royal Blues top after three games as previous leaders Hoffenheim crashed at Bayer Leverkusen.

"That was not great game, but we showed plenty of character," said Schalke coach Fred Rutten. "We showed good organisation in defence and could have won 2-0."

Having earned their second promotion in two seasons, Hoffenheim had shocked the German league by taking an early lead at the top of the table with wins over Borussia Moenchengladbach and Energie Cottbus.

But two second-half strikes by Germany striker Stefan Kiessling ended Hoffenheim's hopes on Saturday despite a brief fightback as they went down 5-2.

"Over the entire 90 minutes, Leverkusen earned their victory," said Hoffenheim coach Ralf Rangnick.

"We knew before the game we were playing a top side, we simply made too many errors."

Hamburg are second in the table, and level on seven points with Schalke, after coming from behind in Bielefeld to claim a 4-2 win.

The north German club, who signed Germany defender Marcell Jansen for eight million euros (11.7 million US dollars) from Bayern Munich on Thursday, found themselves 2-1 down at Arminia Bielefeld at half-time.

But a second goal from Bastian Reinhardt on 50 minutes put Hamburg level before their Croatia striker Ivica Olic gave them the lead on 64 minutes with a right-footed shot past Bielefeld goalkeeper Dennis Eilhoff.

And Czech Republic midfielder David Jarolim sealed the win with a fourth goal on 77 minutes.

"We were a bit naive in conceeding the goals early on, but I didn't worry," said Hamburg coach Martin Jol. "We created so much pressure in the second half time that the goals simply had to come."

Despite being drawn with Inter Milan in Group B of this season's Champions League competition, Werder Bremen suffered the humiliation of being humbled 3-2 by newly promoted Borussia Moenchengladbach.

"Gladbach deserved the win," said Bremen coach Thomas Schaaf. "They fought very aggressively and worked hard. Those were all things which were missing to us. We have taken an enormous step backwards as a result."

Bremen have got off to a slow start this season with draws against Arminia Bielefeld and Schalke.

Having found themselves 3-0 down at Moenchengladbach, Bremen's Peru striker Claudio Pizarro scored 11 minutes from time before Diego's freekick in the 89th minute gave the home fans a nervous wait in the dying minutes.

Also on Saturday, Wolfsburg drew 2-2 with Eintracht Frankfurt while Borussia Dortmund are up to third in the table, also on seven points, with a 1-0 win over Energie Cottbus.

Cologne's Turkish defender Umit Ozat was given a clean bill of health by doctors and released from hospital on Saturday after collapsing during his side's 2-0 win at Karlsruhe on Friday night.

Ozat, 31, lost consciousness after 25 minutes of the match for no apparent reason and was stretchered off after teammates signalled to the bench he needed treatment. The match resumed five minutes later and Cologne went on to win 2-0.

Defending champions Bayern Munich have their chance to pick up their first league win of the season on Sunday when they face Hertha Berlin at the Allianz Arena and Stuttgart host Hanover.