my @Array;
$Array[0] = "1,5";
$Array[3] = "3,9";
$Array[2] = "3,4";
$Array[1] = "6,2";
$Array[4] = "8,1";

@Array = map {
    join ',', @$_;
} sort {
    $a->[0] <=> $b->[0] or $b->[1] <=> $a->[1]
} map {
    [split /,/]
} @Array;

use Data::Dumper;
print Dumper \@Array;

##</code><code>##

my @Array = (
    [1, 5],
    [6, 2],
    [3, 4],
    [3, 9],
    [8, 1],
);

@Array = sort {
    $a->[0] <=> $b->[0] or $b->[1] <=> $a->[1]
} @Array;

use Data::Dumper;
print Dumper \@Array;