Pro-Western incumbent Boris Tadic won Serbia's presidential election Sunday, edging an ultranationalist ally of former President Slobodan Milosevic by a narrow margin. The state electoral commission and independent vote monitors said that Tadic won about 51 percent, while extreme nationalist Tomislav Nikolic had 47 percent. The remaining ballots were invalid. "Serbia has shown its great democratic potential," Tadic said in his victory speech in downtown Belgrade in front of thousands of cheering supporters. He praising Nikolic for "the number of votes he has won."