Croatian striker Mladen Petric gave Hamburg the lead three minutes before halftime , then two bad second-half mistakes by Per Mertesacker gave Peru striker Paolo Guerrero Borussia Dortmund return to winning form with a 2-0 victory at home to St. Pauli . German leaders now have a 13-point advantage over Bayern Munich and Bayer Leverkusen . Germany has won its last three games in all competitions this season -- including the Champions League final against Real Madrid on Tuesday night. Hanover consolidate fourth following 3-1 win over struggling Kaiserslautern .
Borussia Dortmund return to winning form with a 2-0 victory at home to St. Pauli . German leaders now have a 13-point advantage over Bayern Munich and Bayer Leverkusen . Germany has won its last three games in all competitions this season -- including the Champions League final against Real Madrid on Tuesday night. Hanover consolidate fourth following 3-1 win over struggling Kaiserslautern .