A late strike from Axel Witsel earned Borussia Dortmund a scarcely deserved 1-0 win away to Mainz on Wednesday and sparked the Bundesliga title race back into life. Witsel guided in an 87th minute free-kick from Giovanni Reyna at the back-post to secure victory after a largely uninspired performance from visitors Dortmund. But they have still moved within four points of stumbling leaders Bayern Munich with eight games to play, including a head-to-head showdown between the pair in Munich on the weekend of April 22/23. “Sometimes you can’t play beautiful football, you just have to win,” Witsel t…