Berlin - With all eyes set on the Matchday 13 Klassiker, it is rather easy to forget that not Borussia Dortmund, but Bayer 04 Leverkusen are currently FC Bayern München's closest rivals for top spot in the Bundesliga.

Sami Hyypiä's charges were ruthlessly efficient in the hard-fought 1-0 victory at the Olympiastadion, where Stefan Kießling's eighth goal of the season proved decisive in the Rhinelanders clinching a fourth victory from their last five matches.

Kießling critical


"Defensively we played well, and we managed to score one goal more than the opposition," commented Bayer head coach Sami Hyypiä, and who had good reason to be happy with his side's exploits in the German capital. The hosts enjoyed 58 per cent of the possession and had three times as many attempts on goal (twelve) as die Werkself (four). "Hertha were a strong opponent," admitted sporting director Rudi Völler."You don't just come here and win easily."

Kießling was similarly critical with his side's performance, but tried to focus on the positives. "We were made to work until the very end, but it's certainly one of our qualities that we're capable of putting in extra effort when things don't go to plan," said the 29-year-old, who already had his sights set on Leverkusen's next challenge in the UEFA Champions League against Manchester United FC on Wednesday. "We'll have to be just as alert [against United]."

'Make life tough for Bayern and Dortmund'


It wasn't all sunshine and roses for Leverkusen on Saturday, however, with the news that in-form Germany winger Sidney Sam will be unavailable for Bayer's upcoming Champions League Group A encounter after tearing a muscle against Hertha just four minutes into the match. "His absence is a real setback," said Völler. With Leverkusen sitting in second place, they could qualify for the knock-out stages on Tuesday. "It's the biggest game for us in the Champions League so far," admitted Völler. "Even without Sam we'll just have to give our all."

Asked whether first place could also be within reach domestically this season, Völler remained low-key. "We have to be realistic. Dortmund are shaken by injury woes, but they are a really strong side and reached the Champions League final last year." Nevertheless the 53-year-old didn't shy away from outlining Leverkusen's own ambition. "We're trying to make life for Bayern and Dortmund as tough as possible. We've certainly been doing well in that respect so far."

Andre Anchuelo / Felix Seaman-Höschele