A Berlin court will on Friday start hearing an appeal by Alexander Zverev against a fine for allegedly assaulting his ex-girlfriend, as the German tennis star competes at the French Open. Zverev, the world number four player, received a 450,000-euro ($487,000) fine in October but has appealed the ruling. The 27-year-old indicated last week that he would skip the opening of the proceedings in Berlin, which falls in the middle of the two-week French Open. "I believe in the German system," he told reporters. He had not been ordered to appear personally in court in Berlin. The alleged victim, however, has been invited to give testimony at the start of the trial, which will last through mid-July.