Colombia have three points while Poland can not advance after losing their first two games.
With the two sides having drawn 2-2 in their group fixture, meaning their head-to-head record was also level, it then went to the next deciding parameter - fair play.
This marked the first time in World Cup history that a team progressed out of the group stage via their Fair Play record.
"We know we already have 15 million Senegalese behind us and now we have all the continent", added Napoli's Koulibaly.
Previously, a random drawing of lots would have decided which team would advance between Japan and Senegal. Yep, Senegal have been eliminated because they picked up more yellow cards that the Japanese.
Senegal were given two yellow cards in their opening win over Poland, three in the draw with Japan - including two in second-half stoppage time - and one on Thursday before Colombia's goal brought the tiebreaker into effect.
He said: 'Deciding it on bookings is mad.
Fans pay big money to attend World Cup matches for the experience and to be entertained but neither Japan and Poland cared about that on this occasion.
With six yellow cards in three group games, Senegal were eliminated because Japan had only been issued four, leaving Africa without a representative in the last 16.
"I think it should be more of a positive thing rather than pressure", said Koulibaly, when asked if there was pressure on the Teranga Lions to advance.