Demarco's unbeaten streak is 15-0-1 with 10 knockouts, including 12 consecutive wins, since losing a six-round, majority decision to Anthony Vasquez in February 2006.
[2] DeMarco's first chance at being world champion was unsuccessful after he was stopped by the late Edwin Valero of Venezuela to retain his WBC Lightweight belt.
DeMarco later stated, “I'm a Mexican fighter, I never wanted to quit but my trainer saw that Edwin was just a better fighter.” When the fight ended, Valero was eight points up on the scorecards of all three judges.
On October 15, 2011, DeMarco stopped former two division champion Jorge Linares in the 11th round to claim the vacant WBC Lightweight title.
This fight took place at The Venetian Macao in Macau, SAR on the undercard of Manny Pacquiao vs. Chris Algieri on HBO PPV.