AZ were poor in the first 45 minutes but improved after the break and eventually secured the victory with two goals in the final 20 minutes.
Ralf Seuntjes first put through his own net before Hatzidiakos made the result safe and the Greek defender was pleased with the eventual outcome after a difficult start.
He said on the club's website: "We started very badly. I personally also made a mistake which gave them a big chance but we picked up the second half well together.
"We always keep working and the results are good, if feels very nice."
The win moves AZ back up to second in the table, but they're still eight points adrift of leaders PSV Eindhoven.