Borussia Monchengladbach ended their eight-game wait for a win in the Bundesliga with a somewhat fortunate 1-0 triumph over 10-man Mainz.Andreas Christensen scored the only goal of the match in a goalmouth scramble after he had spent much of the game defending resolutely against Karim Onisiwo.The Foals rode their luck and had a controversial offside decision to thank for ruling out what would have been a Pablo De Blasis equaliser late on.Still fuming from that decision, Mainz lost Jean-Philippe Gbamin to a late red card as they came away from the Borussia Park Stadion empty-handed, but full of regrets.ends