Generally speaking, that's correct. The small parties don't do so well under PR, but sometimes it can work for them. A good example is the United Kingdom. In the last election, the Scottish nationalist party was hugely overrepresented. Even though their overall strength across the U.K. is not great, they're the dominant party in Scotland, so they won almost every seat there. So for some small parties with concentrated regional strength, first past the post can work to their advantage.
On July 26th, 2016. See this statement in context.