Good idea - especially if it is in a loop. Instead of all three regexes every time, it'll do a maximum of 3.

In order to get the same results, however, the three regexes need to be reversed. In bh_perl's example, when the first match and the last match succeeded, $1 and $2 are set in the third match. In your example, if the first match succeeds the third is never evaluated so $1 and $2 are set by the first match. Reverse the three matches and the results will match the OP's.