Borussia Dortmund returned to winning ways 2-0 at Union Berlin on Saturday to keep fourth place in the Bundesliga in a duel with RB Leipzig who triumphed 4-1 in Bochum. Union had shown rising form in recent weeks to rise into midfield after a disastrous start into season but Karim Adeyemi’s effort into the top corner in off the bar in the 41st and Ian Maatsen in the 90th won it for Dortmund. Dortmund rebounded from last week’s 3-2 home defeat against Hoffenheim and in fourth remain one point ahead of Leipzig who had to play catch-up in Bochum after falling behind from Maximilian Wittek’s free-…