[1] Montantes' career began in 1990 with a win against Norberto Riviera followed by a loss to Jose Vilarino.
However, following the loss to Vilarino, Montantes put together a string of 22 straight wins against ever-improving competition.
His last two fights were losses to well-known fighters Acelino Freitas and James Crayton.
On the night of September 26, 1997, Montantes was fighting James Crayton in Las Vegas, Nevada.
Knocked out violently in the fifth round,[2] Montantes suffered a brain injury and never regained consciousness.