The NWA World Welterweight Championship is nominally a Mexico based championship, having actually been created before the formation of the NWA (and EMLL joining the NWA.)
The championship appeared to be forgotten after it was vacated in 1992. Misterioso was the champion of the time, by left in the mass exodus to AAA. CMLL had recently created it's own CMLL World Welterweight Championship in 1992 and had be considering merging the two championships. Instead, they just allowed this championship to stay empty.
Three years later, Negro Casas won a match for the vacant championship over El Hijo del Santo, as part of their infinite rivalry. However, CMLL was still not intending to use the belt; Negro won the belt to provide another champion for the J-Crown Octuple Junior Tournament and Championship. The championship changed many times as part of the tournament and the length of the championship.
After the J-Crown broke up, the championship ended up as a possession of various Ultimo Dragon promotions and off-shoots. It was widely reported Dragon purchased the NWA World Middleweight Championship from CMLL around this period, so the same may be true with this title. This belt was used as part of Ultimo Dragon's Toryumon promotion during it's early years, until it was ultimately replaced by the promotion's own championships.
When this championship was dropped for Toryumon, it disappeared for three years before resurfacing in as part of Ultimo Dragon's personal shows in Mexico. Hajime Ohara won the vacant championship, defeating the reigning Mexican National Welterweight championLa Mascara. Ohara continued defending the championship on Dragon's occasional shows in Mexico and Japan. He wrestled as a rudo in Mexico, but was obviously Dragon's protege and top remaining student.
Ohara briefly lost this championship to Super Delfin and won it back, mostly unnoticed by the lucha libre audience. While the championship was mentioned in Ohara's CMLL matches (usually second or third on the card), it was treated as a title belonging to Ultimo Dragon's Dragon Gym shows, and not used for any CMLL feuds or rivalries.
This status quo came to an end in November of 2007. Ohara was suddenly in the semimain matches and feuding with (and losing to) La Sombra. After two weeks of trios matches, Sombra was given a title shot and won the championship. At age 18, La Sombra appears to have become the youngest NWA World Champion of all time. While his championship reign has also lacked a notable feud, winning this belt has been seen as a sign CMLL has much larger plans for him down the road. It's also possible an indication CMLL received ownership of the belt back from Ultimo Dragon.
