BERLIN (AFP) Bayern Munichs seven matches in 21 days, including their epic Champions League win over Manchester United, caught up with them on Saturday as they laboured to a 1-1 draw with Bayer Leverkusen. The result allowed them to open up a two-point lead on Schalke, who slumped to a 4-2 defeat at relegation-haunted Hanover, in the race for the German league title with four games left. Louis van Gaals Munich side also have a six-point lead over third-placed Leverkusen and remain on course for a Champions League, Bundesliga and German Cup treble. It was a very even match with few goal-scoring chances, said van Gaal. Bayer created the better chances and they would have hoped to get more out of the game. We gave too many balls away, which allowed Leverkusen to put us in a few dangerous situations. But we are two points ahead of Schalke and six in front of Leverkusen. Its in our hands. Bayern dominated large parts of possession on Saturday, but rarely troubled Leverkusen goalkeeper Rene Adler. Leverkusen came into the game on the back of three successive defeats and they had two good chances in the first half through Eren Derdiyok and Tranquillo Barnetta. But it was Bayern who took the lead in the 51st minute when Gonzalo Castro fouled Franck Ribery and Arjen Robben, who scored the crucial Champions League away goal at Old Trafford in mid-week, converted the penalty. Leverkusens top scorer Stefan Kiessling then headed against the post in the 58th minute before they drew level a minute later. A free-kick from Toni Kroos, on-loan from Bayern until the end of the season, came back off the crossbar and Arturo Vidal tucked away the rebound. Schalkes title hopes suffered a second successive setback when they slumped to a shock 4-2 loss at struggling Hanover. The result came on the back of last weeks 2-1 loss to Bayern. Hanover, coached by former Schalke boss Mirko Slomka, went into the game without a win in the last month, but they led 2-0 at the break after an own-goal from Heiko Westermann and the first of a brace from Ivory Coast star Didier Konan Ya on the half-hour mark. Schalke, seeking a first German title since 1958, pulled back to 2-2 within seven minutes at the start of the second half through an Edu Goncalves strike and a penalty from Croatian international Ivan Rakitic. Hanover, who are third from bottom of the table, restored their lead in the 80th minute through captain Hanno Balitsch before Konan Ya added a superb, solo goal in injury time. Werder Bremens bid for Champions League qualification received a big boost when they thrashed Freiburg 4-0 and fourth-placed Borussia Dortmund slumped to a 1-0 defeat at Mainz. Stuttgart climbed to sixth place above Hamburg, who visit Bochum on Sunday, after winning 1-0 at bottom club Hertha Berlin. Polish international midfielder Adam Matuszczyk was on target twice for Cologne in a 2-0 victory at Hoffenheim that moved them further clear of the relegation zone.