On October 8, Benoit made his return at No Mercy, defeating William Regal in a surprise match. Later that week, he won his fifth United States Championship from Mr. Kennedy. Benoit then engaged in a feud with Chavo and Vickie Guerrero. He wanted answers from the Guerreros for their rash behaviour towards Rey Mysterio, but was avoided by the two and was eventually assaulted. This led to the two embarking on a feud with title matches at Survivor Series and Armageddon, matches that Benoit won. The feud culminated with one last title match as a No disqualification match, which was also won by Benoit. Later, Montel Vontavious Porter (MVP), who claimed that he was the best man to hold the United States title, challenged Benoit for the title at WrestleMania 23, where Benoit retained. Their rivalry continued with similar results again at Backlash. At Judgment Day, however, MVP gained the upper hand and won the title in a two out of three falls match, thus ending the feud. Benoit would wrestle MVP one last time at Saturday Night's Main Event XXXIV on May 28, (aired June 2), in a winning effort in a tag-team match where Benoit partnered with Batista and MVP partnered with then-World Heavyweight Champion Edge. He would then wrestle Edge in his last match on the SmackDown! brand in a losing effort on Raw.