The question was for a match in list context

(@match) = ( $_ =~ /.../g )

which returns the matches as a list into an array.

i.e. $match[0]=$1 ( see perlop ¹ )

I didn't want to confuse with more details than necessary...

update

well actually the /g modifier isn't necessary and might produce too many matches...

  DB<110> @matches = ('abcd' =~ /(.)(.)/)
 => ("a", "b")

  DB<111> @matches = ('abcd' =~ /(.)(.)/g)
 => ("a", "b", "c", "d")

  DB<112> $matches[0]
 => "a"
[download]

¹) perlop#Regexp-Quote-Like-Operators

* Matching in list context

If the "/g" option is not used, "m//" in list context returns a list consisting of the subexpressions matched by the parentheses in the pattern, i.e., ($1, $2, $3...).