Complex sentence: López holds a number of records in the division, including the most title defenses with 21, and is the first and (so far) only minimumweight to hold two different major titles simultaneously (WBC and WBO).
Split into simpler sentences: López holds a number of records in the division, including the most title defenses with 21. As well as being the first and (so far) only minimumweight to hold two different major titles simultaneously (WBC and WBO).