Garner’s spot kick levelled proceedings on a sad day at Deepdale after Mathieu Baudry had put the visitors in front before the interval.
Both sets of supporters observed an impeccable minute of silence before kick-off, while all the Preston players had ‘Finney’ on the back of their shirts as Preston remembered their favourite son.
And the hosts had Declan Rudd to thank for not falling behind in the seventh minute when he tipped over Baudry’s close-range shot from Lloyd James’s free-kick.
Garner and Craig Davies both went close for the home side, but it was Orient who hit the front just before the break, Baudry side-footing home.
Dave Mooney then came close to doubling Orient’s lead after the break, but the striker fired over when well placed.
And after Baudry had brought down Davies in the area just after the hour-mark it was left to Garner to dispatch the penalty with ease.
Preston had a glorious chance to seal all three points late on, but substitute Kevin Davies headed wide.