Miss Hungary, Edina Kulcsar, was the runner-up and Miss United States, Elizabeth Safrit, came third in the 64th annual competition, contested by women from 121 countries.
The medical student clasped her hands together in surprise and was crowned by the outgoing Miss World, Megan Young of the Philippines, before a fireworks finale.
“South Africa this is for you,” Strauss said afterwards. “I think I will brace myself for what´s about to happen. It´s a huge responsibility.”