RIO DE JANEIRO — Justin Rose delivered a gold-medal performance in golf worthy of a 112-year wait. In a final round Sunday so tense that no one led by more than one shot, Rose won on the last hole with a 40-yard pitch to 3 feet for birdie and a 4-under 67, giving him a two-shot victory over Henrik Stenson to win the first gold medal in golf since 1904 in St.