my @rows = (
    [qw/ 1 a /],
    [qw/ 6 b /],
    [qw/ 5 f /],
    [qw/ 3 v /],
    [qw/ 9 c /],
    [qw/ 2 a /],
);

my @idx = sort { $rows[$a][0] <=> $rows[$b][0] } 0 .. $#rows;
@rows = @rows[@idx];