For years, Claressa Shields has been dominating the world of women’s boxing. Having already established herself as the greatest female boxer in history, Shields looks to avoid a slip-up as she defends her undisputed middleweight championship against late-replacement opponent Maricela Cornejo on Saturday night. Cornejo is stepping in for Hanna Gabriels, who failed a drug test that she blamed on medication she had to apply to her dog. Shields had already won a dominant decision over Gabriels in 2018 and the entire interest in the rematch hinged on the fact that Gabriels had knocked Shields down in the first round…