The story behind one of the most iconic sports photos of all time

After a decades-long fight with Parkinson's disease, legendary heavyweight boxing champion Muhammad Ali died Friday night at the age of 74.

In one of the most iconic sport images of all time, we see a triumphant Ali returning to his corner after dealing a devastating knockout blow to Cleveland Williams in the third round of their 1966 bout.

The picture, taken by Neil Leifer, was snapped from a camera suspended from the ceiling. Leifer would claim this as his favorite shot of his 40-year career as a photographer.

As in the photo, the two fighters, Ali and Williams, were symmetrical leading up to the bout. Both stood at 6 feet 3 inches, with Williams having a slight advantage in weight and possibly power, but Ali maintaining an important hand and foot speed advantage.

At the moment the picture was snapped, the fighters were posed in much the same way, with the important distinction being that Williams was dazed on his back after being counted out, and Ali was standing tall and facing a cheering crowd.

Here's a clip from the fight: