Once again the Gunners take the lead at the Emirate off a corner kick by Declan Rice and Timber was right on the spot to head home another goal from a set piece.
This is becoming Arsenal trademark.
Though Leeds are not going down without a fight but they have been muscled into submission.
On the stroke of 45 minutes Timber's deft pass found Bukayo Saka running away from Gudmundson and rifled a shot past goalkeeper Perri to make it 2-0 here at the Emirate.