Unbeaten Bayer Leverkusen went eight points clear at the top of the Bundesliga on Saturday after a 2-1 win at Heidenheim while the four other games in the German top flight were again interrupted by fan protests. Right wingback Jeremie Frimpong netted with his left foot after a quick break and Amine Adli rounded the goalkeeper to hand Leverkusen victory ahead of second-placed Bayern Munich going to Bochum on Sunday. Leverkusen beat champions Bayern 3-0 last weekend as they target a first ever Bundesliga title. Xabi Alonso’s side have been one of the stories of the season, but so have frequent …