Johnny Nelson, one of the longest reigning titleholders in boxing, retained the WBO cruiserweight title by beating Vincenzo Cantatore by split decision on Saturday. Nelson, now a ripe old 38, improved to 45-12-2. He has held the title since 1999, longer than any other active boxer except Joe Calzaghe. As usual, Nelson fought defensively with few exchanges, drawing boos from Cantatore's fans in Rome. The Italian was credited with a ninth-round knockdown, but it probably should have been ruled a push. In any event, one judge saw it for Nelson, 116-111 with scores of 115-112 for each boxer canceling each other out. Next up for Nelson could be a passing-of-the-torch fight in England against rising star Enzo Maccarinelli. Cantatore drops to 30-4-1. It was his second failed title bid, as he also lost to Wayne Braithwaite in a bid for the then-vacant WBC title. He claimed to have been robbed this time