Hi Pingu, here follows one of the very many ways to do it.

#!/usr/bin/perl -w
use strict;

    # Saves me from worrying about csv stuff.
    # $results is a reference to a hash.
my $results = {
                  x => [1,3,4,5,6],
                  y => [14,6,7,8,5],
                  z => [6,7,8,5,3]
};

    # first we dereference our hash, then we check
    # our index...
foreach (sort { return $$results{$a}->[0] <=> $$results{$b}->[0]; }
                keys %$results)
{
        print "key = $_\narray =\n";
        foreach my $i (0..4)
        {
                print $$results{$_}->[$i]."\n";
        }
}
[download]

Works like a charm for me. :)