stroke of luck
stroke of fortune

It would have failed, but for a stroke of fortune.

Through a stroke of good fortune, he has a hand transplant.

"I would consider the opportunity a stroke of good fortune. "

No, I think this is more likely a stroke of good fortune.

However, by a stroke of fortune we are able to provide you with a cast list.

But after eight issues, early in 1967, the paper had a stroke of good fortune.

He seems like a man who's enjoyed every possible stroke of good fortune.

It began seven years ago, in what struck him as a stroke of great fortune.

This might be the most significant stroke of fortune that would ever come his way.

A day later I had a stroke of good fortune.