Liu Xiang of China, who was the fastest off the blocks, clinched the bronze, China's third in the world championships, in 13.23s.
These three athletes had finished in the same order in terms of qualifying times in the semi-finals on Friday.
But the form book thereafter was upset a little, with the two other Americans in the event, Larry Wade and Chris Phillips, finishing fourth and fifth.
Márcio Simão de Souza of Brazil, who had the fourth fastest time in the semi-finals, ended up sixth, with China's Shi Dongpeng and Cuba's Yoel Hernández completing the list.