Tanguy Nianzou scored his first Bayern Munich goal on a rare start as the Bundesliga leaders recovered from two straight league draws with an easy 4-0 home win over Union Berlin on Saturday. The defending champions, seeking a 10th title in a row, increased their advantage back to seven points pending Borussia Dortmund’s trip to Cologne on Sunday. Kingsley Coman opened the scoring on 16 minutes with a fast, swerving effort which goalkeeper Andreas Luthe should still have done better with. “We played very well, we played together, we defended together. We were very efficient…and created lots o…