Once Jericho joined the WWF in August of 1999, the feud gradually resumed in matches on the house show cicuit and every so often on TV. Things really started to heat up after King of the Ring 2000 when X-Pac defended HHH's wife Stephanie after weeks of Jericho's verbal assualts.

They fought again on September 7,2000 for apparently no reason. The WWF can't find anything to do with eitehr guy, so they put them in a match. Then, out of nowhere, they start a fued between the two. The September 11 RAW saw the build up for this one when X-Pac interferred in Jericho's match against Triple H and later in the night, Chris Jericho cost X-Pac the hardcore title in a match against Steve Blackman. Unforgiven finally came around and Jericho got the win, but X-Pac got the best of Jericho by kicking his ass after the match. The fued didn't stop there. The night after Unforgiven, they had a re-match first blood match in which X-Pac won by breaking a bottle on Jericho's head. A week later, Jericho got his revenge by pinning Raven in a six man match pitting X-Pac, Raven, and Tazz vs. The Dudleyz and Jericho.

No Mercy brought a steel cage match that everyone hoped would end the fued. Jericho was the first out of the cage thus winning the match. From there, Jericho moved on to a fued with Kane and X-Pac left with an injury.

X-Pac returned the beginning of February 2001 and picked up right where he left off with Jericho only this time Jericho had the IC belt. The first big match was at No Way Out in a four corners IC title match in which Jericho won.