Phew! For the future, I would use Command-H (hide window) as the window goes away and if you hover over the dock, only the word "Safari" comes up. A simple Command-Tab and you're back in business. Either that or you can use what I just did while answering this post and someone came into my office - have another browser window open (and placed in the same place) and use Command-tilde (~) to cycle through the windows.
Kathi
