Matt Ghaffari knows the unbeatable can be beaten, the unconquerable brought to his mighty knees.
He also knows the man to finally end the remarkable winning streak of Alexander Karelin.
"My goal is to wrestle [Karelin]," Ghaffari said. "People buy tickets to see him. I'm 0 and 20 against him, but No. 21 should be the charm."
Before a hyped-up crowd more suited for a rock concert than a Greco-Roman wrestling tournament, the driven Colorado veteran and the Russian universally considered the greatest wrestler of all time moved to within a victory each of a gold-medal super-heavyweight showdown.
Ghaffari beat two good opponents, while Karelin won three times to remain unbeaten in 10 years of international competition.
Karelin was taken into overtime for only the second time in his career before beating Sergei Moureiko of Moldova, 3-0.
Karelin, 28, was more impressive in pinning Finland's Juha Ahokas in the quarterfinals. Because of the uneven brackets--10 wrestlers won in the preliminaries--Karelin had one more match than Ghaffari.
Ghaffari, 34, of Colorado Springs, was joined in the semifinals by Brandon Paulson, a 114 1/2-pound Minnesota redshirt who won twice in his first big international tournament.
Paulson, a three-time junior national champion from Anoka, Minn., and the least experienced of the 10-man U.S. team, pinned Joel Basaldua of Peru in 1:36. He followed that with a 6-1 decision over Ibad Akhmedov of Belarus.
Gordy Morgan and David Zuniga, two of Paulson's University of Minnesota teammates, were each eliminated with two losses.
Derrick Waldroup of the United States won twice in the losers' bracket at 198 pounds to remain in contention for a bronze medal.
Defending champion Maik Bullman of Germany was upset by Vyacheslav Oleynyk of the Ukraine in the 198-pound quarterfinals. Jon Ronningen, the 1988 and 1992 Olympic champion from Norway, went 0-2 and out at 114 1/2 pounds.