After beating American Ryan Harrison in Cincinnati, 6-2, 6-3, world No. 1 Novak Djokovic says he like the teenager’s upside. "Ryan has a lot of potential in his game," Djokovic said. "He knows when to use the opportunity to come to the net, he mixes up his serve, his serve is quite good. Today he didn't have quite a high first serve percentage, so it didn't help him that much. But if he gets that serve 60 percent, 70 percent in, he can be really dangerous to anybody. I think he's a great fighter. He's committed to the game, which is really important…. His emotions are showing me that he wants to win and he's out there to win, not just play his best tennis. That's something that I like about him."