use Sort::Key::Top qw(rikeytopsort);
my @sorted = rikeytopsort { $_->[2] } 3 => @masterArray;
#            rikeytopsort means...
#            r    => reverse (descending) order
#            i    => the key is an integer
#            key  => use a key extraction block
#            top  => get the top n elements
#            sort => sorted