Warburton, from Colwyn Bay, described his win over Heaney at Manchester’s Co-Op Live Arena in March as “surreal”.
He fought before a crowd of 15,000, which included over 2,000 of Heaney’s supporters from Stoke-on-Trent, on that triumphant night.
“There was a lot of pressure on me to win the fight – I don’t know where I’d have gone if I’d have lost it,” Warburton said.
“But I took the opportunity with both hands, dealt with everything in the best possible way I could and got the job done.
“People didn’t expect me to perform the way that I did.
“But my management, my team around me, they all believe in me and they know what I’m capable of. On the night I showed it.”
With no rematch clause stipulated in the deal struck for Warburton’s previous meeting with Heaney, the southpaw boxer had eyes on other prizes.
But one phone call altered the Welshman’s plans, and left him with an easy decision.
“We were looking at maybe taking the next step ahead, maybe potentially fighting for another title or something like that,” Warburton explained.
“We had a few opportunities that we turned down. We weren’t in any rush.
“Then we got a phone call to say that Nathan Heaney said that he wants his last fight to be against you. Would you take it?
“We just said yes straight away. It’s just an opportunity that you can’t turn down, so we took it.”