‘I gambled on Ali getting a knockout, fastening my camera to the lights way above the ring. And Williams landed flat on his back in a good spot’

Everyone assumes the picture I took of Ali v Liston in 1965 is my favourite – it has even been called the greatest sports photograph of all time. But my favourite photograph I ever took is Ali v Williams, no question about it. It’s the only one of my photographs hanging in my home. I’ve shot everything in my career, from Charles Manson to the pope, but I’ve never taken a better photograph than this.

I shot 35 of Ali’s fights. I was ringside for Sports Illustrated when he won the world title in Miami in 1964 and my photo for that made the cover, so by the time of the Cleveland Williams fight I was pretty well established. Williams was a very promising heavyweight but the underdog; the main thing I remember from that night was how excited I was about how I was going to shoot it. Putting a camera over the ring goes way back, maybe to Joe Louis’ days, certainly Sugar Ray Robinson. But the lights that lit up those fights were always 20-25ft over the ring and there was no lens wide enough to capture the whole scene; photographers used fisheye lenses so the ring never quite looked square.