Like this?

22:06 >perl -wE "my $s = 'abc1abc2abc3abc4abc5zz'; $s =~ /.*(abc\d)/; 
+say qq[matched $1] if $1;"
matched abc5

22:07 >
[download]

The greedy quantifier in the regex term .* eats up as much of the search string as possible, thereby ensuring that the last match is found.

Hope that helps,