So I was flying around doing lowbie pet battles, and I was in Searing Gorge. My pet battle ends, and suddenly a hunter opens on me - stampede, full cooldowns - I was caught completely off guard (on my shadowpriest). Fortunately I had Void Tendrils at the time, so I root all the pets and move out of them - and I Body and Soul toward the nearest stone tower (overlooking the gorge), so I can line of sight him during his cooldowns - given his health I knew he was geared (600k+ ish and this was at least last season, if not before, and he didn't have Fort/Dark Intent) - and given the Duelist title I knew he wasn't just a PvE'r.
I line of sight, I'm low on health - but I'm ahead of him - I manage to ring-around-the-rosie with him long enough to heal up a bit, finally I went up the tower and leapt off - but landed on a little lip below - he missed the lip and fell to a lower level. I healed up before he got back to me: he was still at full health (too worried about myself to dot him). So, I'm out of defensive cooldowns (had to disperse and fear twice when he caught up to me on the tower). The fight begins, both at full health, he's out of offensive cooldowns (granted it's been at least a minute or more since he blew them all now) - and I'm completely out of defensive cooldowns - but we're both at full health.
I manage to juke him around the tower enough to get him low (Fear -> Mind Blast ->DP) - at which point he scatters me and rocketboots into the distance. I'm an engineer too - scatter ends, I rocket boot after him, but he's got a lead on me. He mounts, and begins to fly straight up into the air. I mount, and fly after him - but he's ahead of me. We end up chasing for some time - but eventually we reach the top of the world, and I've gained some distance on him, I'm ~15-20 yards behind him now - but obviously neither of us can attack while flying.
He suddenly dismounts, turns, and begins firing arrows into me at the top of the skybox - then Goblin Gliders. I Goblin Glider and begin to do the same - it's looking bad for me because Hunters have way better instant damage than Spriests, and he opened first - we're both around half health now - the lead I had from the tower fight on the ground instantly lost in his instant cast salvo in the air.
Knowing I can't beat him like this, I focus more on the flying - and eventually I end up behind him, in his blind spot - he tries hard to shake me but I keep focus on staying literally like 1-5 feet behind him - right on top of him, right behind him - the goblin glider turning radius making it hard for him to get a line on me. Spamming shadow word: pain for like ~5k damage second, I eventually build up 3 shadow orbs, and DP him - now his health starts falling - he hits execute range, I double tap Shadow Word: Death, he falls to his death deep into the gorge. I soar off and just make the nearest lip of the gorge (I'm like, 21% health myself - I could almost feel him spamming Killshot).
It was only the second most epic world pvp battle I've had in a decade of WoW! The whole battle, start to finish - must have been almost 10 minutes.
The only thing that saddens me about it is, I actually had Fraps enabled at the time - but I never hit record at the start of the fight because I was too caught off guard by his opener, and then too focused on keeping up with him to remember.