Serbia's pro-Western president declared victory in Sunday's parliamentary elections - a stunning upset over ultranationalists who tried to exploit anger over Kosovo's independence and thwart the nation's ambitions to join the European Union. "This is a great day for Serbia," Boris Tadic proclaimed after an independent monitoring group that carried out a parallel vote count nationwide said his bloc won 39 percent - about 10 percent more than the ultranationalist Serbian Radical Party. "The citizens of Serbia have confirmed Serbia's European path," he said. "Serbia will be in the European Union. We have promised that, and we will fulfill that." But Tadic said he wasn't celebrating, because his nationalist rivals could still team up against his Coalition for a European Serbia and try to form Serbia's next government. "I'm sure that those who wanted to return Serbia to the 1990s will try to overturn the electoral will of the people, but I will not allow it," he told supporters, adding that he would propose a new prime minister from his own bloc.