[Konstantinos]

I had also tried something similar to insert data for racetop (top5) and then directly delete anything but keep 5 best time rows. The result was the same as yours. Even though in phpMyAdmin was executed without any problems so I just send 2 queries instead.

I'm not sure as I never tried, if something like this would work: https://dev.mysql.com/doc/refman/5.0/en/begin-end.html

@Stev: I think UNION is used only for SELECT queries, correct me if I'm wrong.