Diego ricardo Santillan started his career aged 34 on September 2008. After 23 fights, Santillan remains unbeaten with no sign of being beaten after building up his record of 23 wins and a career lasting 2 years so far. Santillan's longest KO streak is 8 fights long out of his 23 career fights.
Santillan proved he was made for the pro ranks in his debut against Diego Tolaba, becoming the first person in Tolaba's 0 fights to stop him. The fight ended in round 1 of 4. Santillan continued on his journey to success by fighting 2 times in 2008, 2 times in 2009 and 8 times through 2010 and 2011 beating fighters such as Diego Tirado, Reginaldo Martins carvalho and Guillermo osvaldo Soloppi in his next 12 fights.
Juan pablo Segundo was up next for Santillan on December 5th, 2008. Santillan continued with his winning streak by beating Segundo. Santillan was the 3rd person to go the distance with Segundo. Santillan fought Juan pablo Segundo in 2008, the result was via UD. Santillan then went on to win a further 6 fights taking his record to 8 wins, 0 losses and 0 draws.
On June 5th, 2010 Santillan fought and beat Guillermo osvaldo Soloppi (13-0-0) to continue his unbeaten streak. Soloppi was stopped in the 5th round via KO crowning Santillan as the first person to stop this opponent. Santillan's win streak of 9 rose to 16 following 7 great wins, becoming the 6th person to go the distance with Miguel angel Canido, 5th person to stop Nelson daniel Monte and 4th person to stop Roberto Santos de jesus (Round 3 KO).
On May 18th, 2012 Santillan fought and beat Oreste bernabe Nieva (11-0-0) to continue his unbeaten streak. In what was a true showing of Santillan's technical ability, Santillan got the decision in the 8 round fight, and became the first person to beat Nieva. 2 wins followed taking Santillan's winning streak to 19 wins.
Next was Pablo Canido on July 5th, 2013 where Santillan took the win continuing his unbeaten streak. Continuing his career, Santillan fought Pablo Canido in 2013 over 6 rounds. Santillan was the 5th person to go the distance with Pablo Canido. Santillan's wins continued and went from 20 wins to 21 after he then defeated Lucas rafael Baez.
Manuel Neculhueque was Santillan's next fight on November 1st, 2013 and also his next win in his career. Santillan was the first person to stop Manuel Neculhueque and he did it in the 4th round via TKO.
The unbeaten run continued with the defeat of Diego luis Pichardo liriano in his latest fight on June 6th, 2014, taking his winning record to 23 wins. Santillan became only the 5th person to defeat Diego luis Pichardo liriano in his 17 long fight career, taking his win tally to 23 via the judges decision (UD, round 10).