Photographing a watch with one single light is not impossible. Here is a tutorial how to do it.
Watch photography is one of things because of different materials, textures and shapes on a tiny surface. Nowadays watch photos are mostly composite pitures: the watch is being photographed in parts and the single photos are composited to one final in post-processing.
So as the tutorial videos show below. The first video shows the lighting with one light and cheap accessories, the second shows the compositing process.