Dhaka, Dec. 14 -- Second-placed RB Leipzig slipped up with a 3-1 loss at Union Berlin on Friday for their third Bundesliga defeat of the season and missed the chance to close the gap on leaders Bayern Munich.Leipzig stay on 29 points, eight behind Bayern who can extend their advantage with a home win over bottom side Mainz 05 on Sunday when Borussia Dortmund, third on 28, visit Freiburg.Leipzig never really found their footing in the first half and Union had the best chance on the stroke of halftime when Janik Haberer's effort with his knee sailed narrowly wide.Oliver Burke, however, did not miss as he unleashed a left-foot shot into the top corner that left goalkeeper Peter Gulacsi frozen on the spot in the 57th to put the hosts in front.L...