Robert Prosinečki did a hop, skip and a jump. He hugged a member of his coaching staff then turned back towards the field of play and raised a celebratory fist in the air. Once the elation subsided, he pulled at the lapels of his suit jacket, took in a deep breath and hoisted his trousers up a bit as though to compose himself. Try as he might, Prosinečki couldn’t keep the emotion in and incited the crowd once more.   A few moments earlier Red Star striker Filip Kasalica had been put through on goal. This was a chance for individual glory in the Belgrade derby. Challenged by Partizan defender Nemanja Rnić, he stayed strong and held his ground, but by now the ball…