"The Saint Meets His Match" (AKA "Angels of Doom") is a solid early Saint novel. It's no match for "The Saint in New York", but it is engaging and witty. The book has some surprising twists, including which side of the law The Saint is working for, and a few harrowingly exciting scenes, including one in a cave where the water is rising and Simon and Jill are enchained. The Saint finds his way in and out of trouble in the usual extraordinary ways. (If he's always extraordinary, is that still extraordinary? I guess so, in comparison to everyone else, yes!)
If you like Saint books, this is a fine addition to your library. If you're just curious, or dipping your toes in the pool for the first time, try "The Saint in New York".