In scoring a decisive decision win over former 130-pound titlist Joseph Diaz (32-2-1, 1-1-1 in last three), William Zepeda established new all-time CompuBox records at lightweight for total punches thrown (1,536, exceeding Efren Hinojosa's 1,507 against Lamar Murphy on 3/16/01), jabs attempted in a round (89 in round two, breaking Lamar Murphy's 88 in round two against Angel Manfredy on 8/3/01) and attempted jabs (787, surpassing Stefano Zoff's 673 against Julien Lorcy on 8/7/99).

His exceptional work rate (128 punches per round to Diaz's 50.6), diverse jabbing (65.6 attempts/13.1 connects per round; 86 body connects, 86 head connects) and incredible stamina enabled him to dominate the contest aesthetically and statistically.

He led 398-176 overall, 157-49 jabs, 172-62 body and 241-127 power despite trailing 29%-26% overall and 39%-32% power. Save for a moment when Diaz briefly wobbled Zepeda, the Mexican was in full command as his ceaseless combinations opened several cuts and prevented Diaz from establishing any rhythm. The scoring was 119-109 (2x), 118-110.