Borussia Dortmund opened up a seven-point lead at the top of the Bundesliga tonight with a 2-1 win over Mainz at the Westfalenstadion.

Jakub Blaszczykowski put the Westphalians ahead in the 26th minute and they missed numerous good chances to double their advantage before their former striker Mohamed Zidan levelled with 15 minutes remaining. But Shinji Kagawa scored the winner in the 77th minute as Dortmund took another step towards a successful defence of their Bundesliga title.

Buoyed by Bayern Munich's 2-0 defeat at Bayer Leverkusen, Klopp told Sky before the game that his side had "cracked open the champagne" on the bus to the stadium. He was only joking, not wanting to take anything for granted, but he knew that a win would give his side a seven-point cushion over the Bavarians at the top of the table.

"I just hope we are able to put that (Bayern result) out of our heads like we have done in the past," added Klopp, who was not let down by his team.

Blaszczykowski put them in front in the 26th minute when a blocked shot from Kagawa fell to him and he left Christian Wetklo no chance with a shot into the top left-hand corner. The Polish midfielder lifted another chance over the crossbar minutes later as Dortmund started in dominant fashion.

Mainz did well to stay in the game before stunning the hosts with an equaliser midway through the second half. Zidan, who left Dortmund during the winter break extended his remarkable record since returning to Mainz with his fifth goal in as many games. 

Adam Szalai laid the ball off for the Egyptian, who drilled his shot low towards the bottom corner with Roman Weidenfeller unable to keep the ball out despite getting a hand to it. Zidan did not celebrate, as he had promised on the eve of the game.

However, Kagawa restored Dortmund's advantage two minutes later. Lukasz Piszczek sent in a low cross from the right and the Japanese midfielder shot in off the underside of the crossbar at the near post to seal Dortmund's eighth straight win - a new club record.