A Western Australian woman said she has something unusual to thank for her nearly $50,500 lottery win -- a broken watch.

The Redcliffe woman told Lotterywest officials she suspected her watch's battery was dead, so she took it to a local store and was surprised to discover the price of the repair was less than expected.

"I went to get the battery changed in my watch. It was cheaper than I thought, so I also got a scratchie," the player said. "It was a spur of the moment decision and the best thing I ever did."

The Super World Play ticket turned out to be a $50,479.50 top prize winner.

The winner said she plans to use the money to pay off her home and help her children. She said that, despite the windfall, she is satisfied with her repaired watch and will not be buying a new one.