Colombia's first division opened an investigation into possible match-fixing on Monday, two days after a scandal over promotion caused widespread indignation in the South American nation.
Second-tier club Llaneros played Union Magdalena at home on Saturday and were leading 1-0 until the 95th minute, when the visitors scored twice in succession.
Video of the winning goal appeared to show the Llaneros players backing off their opponents and allowing them to score.
The result meant Union Magdalena were promoted to the top tier first division, the Dimayor league, ahead of Fortaleza, who lost 2-1 at home to Bogota on the same night.
"Despite the evident facts that all Colombians and the entire world have seen, we're going to respect due process and we're going to act within the regulations and statutes that we have here in Colombia as do FIFA," Dimayor President Fernando Jaramillo said on announcing the investigation.
If the clubs are found to have breached sporting integrity they risk being kicked out of the league, Jaramillo added.
In a statement on Saturday night, Llaneros welcomed an independent inquiry and said it was undertaking its own investigation. Union Magdalena did not respond to requests for comment.
Jaramillo also said he would ask law enforcement to decide whether any crimes had been committed.
The country's President Ivan Duque was one of many prominent Colombians who commented on the suspicious goal that went viral.
Duque called it "a national embarrassment" and national team players came to the same conclusion, with Juan Cuadrado, captain of Italian side Juventus, and his Colombian team mate, Matheus Uribe, expressing their distaste at the events.