VfB Stuttgart rebounded from mid-week German Cup heartbreak with a comfortable 3-1 Bundesliga victory over lowly Mainz on Sunday to underline their Champions League ambitions. Maximilian Mittelstädt opened the scoring into the far corner off Stenzel’s cross from the right, and three minutes later Stenzel also set up Jamie Leweling for the second. Both goals came at the start of 15 minutes of first half stoppage time, given after fans had thrown tennis balls and other objects onto the pitch in ongoing protests against plans of the German Football League to bring in a strategic partner. Deniz Un…