Hertha Berlin strengthened their grip on third place in the Bundesliga going into the winter break by beating Mainz 2-0 for their third win in a row.Vladimir Darida put the Old Lady in front 10 minutes before half-time, with Salomon Kalou adding a second 10 minutes into the second half.Vedad Ibisevic supplied both, and he had the ball in the back of the net himself only for the offside flag to deny him.The Bosnian nearly scored with a backheel late on, while Pablo De Blasis hit the crossbar for a meek Mainz side, who managed just two shots on goal all game and could have no complaints about losing at the Olympiastadion.ends