"[1] Asenjo rose to prominence with an initial 17–2 record, primarily fighting in his home province of Cotabato.
He won his first title on 23 May 2009, defeating Tanzanian fighter Sadiki Abdulazizi by way of first-round TKO for the WBO Oriental minimumweight belt.
On 30 April 2011, Asenjo travelled to Mexico City and challenged Raúl García for his WBO minimumweight title.
[2] After six more consecutive wins back home, Asenjo returned to Mexico four years later to challenge WBA (Super) and WBO flyweight champion Juan Francisco Estrada, this time in Mérida.
[3] He was quickly dispatched by the Mexican after his corner threw in the towel in the third round when his right eye swelled up.