Marcel, and I don't really see how you could argue otherwise. He won H2H and has a better résumé outside of their fight at the weight anyway.
Ernest Neto Marcel did defeat Alexis Arguello but Alexis moved on to bigger and better things. Arguello knocked out Ruben Olivares on November 23 1974, then on Alfredo Escalera in 1978, then defeated Jim Watt to win his third title at 135 lbs. Then came his unsuccessful bid against Aaron Pryor at 140 lbs in 1982 and 1983.