Skrillex -- Don't Worry Tiesto ... I Feel Your Pain

Skrillex knows all about hitting his head on stage ... which is why he empathizes with Tiesto who's recovering from a concussion Friday ... when the DJ bonked his noggin on a giant LED.

Skrilly was cruising out of LAX Saturday when he told our photog he pulled a Tiesto back in the day during a gig in Mexico ... but luckily, he didn't have to bail 'cause it was at the end.

Check out the video ... it looks SUPER PAINFUL!