This Sunday WWE icons Brock Lensar and The Undertaker will square off in a clash for the ages at Wrestlemania XXX, but with the help MMA Fighting's archives we can show you the bad blood stretched back further than any recent altercations on Raw.
Lesnar will become the 22nd man to take on the Phenom on the grandest stage of them all this weekend, bidding to end his 21-0 unbeaten run at Wrestlemania, a 'Streak' which has become synonymous with the showpiece WWE event.
Although a simmering rivalry between the pair is something new to wrestling fans, the first sign of visible heat from either man actually came moments after Lesnar during his MMA days at UFC 121 in Anaheim.
The Undertaker was cageside to watch Lesnar defend his UFC heavyweight championship against Cain Velasquez, a fight which the younger, fresher challenger won with unnerving ease.
MMAFIghting.com journalist Ariel Helwani attempted to grab reaction from The Deadman immediately after Velasquez had smashed Lesnar inside a round, which led to an iconic altercation between this Sunday's foes being captured on film.
Check out The Undertaker laying down the gauntlet to Lesnar for the first time all the way back on October 23, 2010 by clicking here.