The act of being totally and utterly destroyed by your opponent. Although the loser may be absolutely "owned", ownage just doesn't do it justice. In Phelps' case, he "owned" world class athletes while at times making it look silly. You see being "owned" could mean that you fought a good fight- better luck next time. But to be Phelpsed is on a whole different level. In this instance, the loser was horribly defeated to the point that there was no purpose for his or her participation in the event.
By way of photographic proof, catching someone doing something incredibly damaging to their own reputation and tagging them on Facebook. As in Michael Phelpsgetting caught hitting a bong.
"I had my junk tucked back between my thighs, and Jessica totally phelpsed me. Now that the picture is out there I will never land gainful employment.