Quintero made his first team debut at the age of 18 on 18 September 2005 in a 1–0 defeat to Atlético Junior. That would be his only first team appearance of the year. in 2006, after being placed on a special vitamin supplement and workout routine to help Quintero bulk up, he was called up to the Tolima first team, which was now managed by Quintero's former youth coach Jorge Luis Bernal. He scored his first goal on 19 February 2006 in a 3–1 win over Boyacá Chicó. Quintero would score his first career hat-trick on 26 February in a 7–3 victory against Envigado F.C. He went on to score 19 times in 42 appearances in his first full season. Quintero and Tolima finished the Campeonato Finalización top of the table, but they lost in the final 2–1 on aggregate to Cúcuta Deportivo. Quintero also made his debut in continental football in 2006, first appearing and scoring in the Copa Sudamericana on 22 August in a 3–1 win over Independiente Medellín in the first leg of the first stage. He would score again on 21 September to give Tolima a 2–2 draw with Mineros de Guayana, with Tolima advancing on away goals. Tolima would advance to the Round of 16 before falling to eventual champs Pachuca.