When The Invasion storyline commenced, Kidman appeared on WWF television as a tweener for the Alliance faction. In July 2001, he won the Cruiserweight Championship from Gregory Helms on SmackDown!. Kidman then defeated the WWF's Light Heavyweight champion at the time, X-Pac, after a Shooting Star Press at InVasion 2001. Kidman was later sidelined with an injury during the Invasion angle and thus did not have as big of an impact as other Alliance superstars. On the October 11 edition of SmackDown, Kidman won the Cruiserweight title back after losing it to X-Pac on an episode of Raw is War in late July.
Kidman turned face after the Alliance broke up. He was drafted to SmackDown! as part of the brand extension, and in his return match defeated Tajiri to win his first Cruiserweight Championship under the WWE brand. Tajiri reclaimed the title at Backlash. At Rebellion 2002, Kidman and his real life girlfriend at the time, Torrie Wilson defeated John Cena and Dawn Marie in an intergender tag team match. He later went on to capture the Cruiserweight Championship for the seventh time (making him the record holder for most Cruiserweight Titles at the time), by defeating Jamie Noble at Survivor Series. Kidman lost the title three months later to Matt Hardy at No Way Out. He spent the next few years as a star attraction in the cruiserweight division, relying solely on his in-ring work and no real gimmick. In early 2004, Kidman began teaming with Paul London, slowly working their way up the tag team ranks. They went on to win the WWE Tag Team Championship from The Dudley Boyz on July 8, 2004. Proving the win was not an upset, they went on to win a rematch for the titles.
Their championship run came to an abrupt end after Kidman turned his back on London. The heel turn played off of a legitimate injury which occurred on an August 24, 2004 taping of SmackDown!, when Kidman's Shooting Star Press unintentionally caused Chavo Guerrero to suffer a concussion. The next week, Kidman was on the top rope ready to hit the Shooting Star Press, but hesitated, climbed down the turnbuckles, and slowly walked backstage overwhelmed with guilt after injuring Guerrero. London was left alone to defend the titles against Kenzo Suzuki and Rene Dupree, and was brutally defeated. London and Kidman fought at No Mercy 2004, where Kidman injured London with a shooting star press while London was strapped to a stretcher. This completed Kidman's heel turn, blaming the fans for wanting him to be more brutal with his in-ring style. Kidman and Guerrero ended their feud upon Chavo's return, the latter being victorious in the final match. Kidman then competed against London over the Cruiserweight title in the coming months. At the start of 2005, Kidman suffered a broken orbital bone, which sidelined him for three months.
Kidman was released from his WWE contract on July 6, 2005.
As of 2010, Kidman is a producer on WWE Raw. He was mentioned by John Cena in the November 22, 2010 episode of the show.