Try using /^(\S+)\s+(\S+)$/ or for a little less broad of a match, try /^(\w+)\s+(\w[-|\w]\w)$/.
For some reason it seems to offset what it returns by the length of the string to the left (ie xyz). If you add another character, it will return an "e" rather than a "d". Whereas if you remove a character it returns the " ".