Serhou Guirassy scored twice to help Borussia Dortmund battle back from 2-0 down and beat winless Bochum 4-2 at home on Friday, sparing more blushes for coach Nuri Şahin. Dortmund were thumped 5-1 at VfB Stuttgart last weekend having started the season well and it looked like the coach would be under real pressure after a woeful first 40 minutes. Bochum, who picked up their first point of the season in last weekend’s 2-2 draw with promoted Holstein Kiel, took a shock lead when a simple one-two released Matúš Bero and his fierce left-foot shot flew in at Gregor Kobel’s near post. It got far wor…