Each time he saw the Superman insignia on Conner, "Match" went into a rage; and at some point during his battle with Superboy, he burns the "S" into his chest. This scenario is very similar to the first comic book encounter of two Superboys. In the DC graphic novel, "Infinite Crisis," Conner Kent encounters Superboy Prime, who unlike him is a full-blooded Kryptonian. Prime is jealous of Conner and continually insists that he is the "real Superboy." After his defeat at the hands of Superman, Prime permanently marks his chest with the "S."
When Match burns the backward "S" into his chest, it makes him resemble the traditional Bizarro character, who was also an imperfect duplicate of Superman, and wore a reversed "S" as his emblem.
The events depicted occur on November 25th.