Former champions Eintracht Frankfurt had luck, efficiency and a great goalkeeper on their side as they claimed a 3-1 Europa League victory at Besiktas on Thursday. Bundesliga top scorer Omar Marmoush converted a 19th-minute penalty after being brought down by Gabriel Paulista to silence the Istanbul crowd. Dina Ebimbe made it 2-0 three minutes later, set up by Robin Koch. Substitute Ansgar Knauff wrapped up matters in the 82nd before Arthur Masuaku got a consolation goal in stoppage time. Koch was lucky to be on the pitch by the time of his assist because he could have been sent off in the 11t…