Senegal further, Ecuador eliminated.
It was the result of the decisive group stage match between the countries in the World Cup in Qatar.
It was a fast-paced opening with Senegal's Idrissa Gueye having a dangerous chance straight away, but it was not until the end of the first half that their lead came.
Piero Hincapie drew a penalty which Ismaila Sarr elegantly slotted home.
In the 68th minute, Moises Caicedo equalized from a corner, but just two minutes later, team captain Kalidou Koulibaly was in a messy situation after a cross.
He controlled the ball and the Senegalese supporters celebrated.
It is the first time since their World Cup debut in 2002 that Senegal have advanced from the group.
They have done that without their injured superstar Sadio Mané.
With their six points, Senegal are second behind the Netherlands and will now face the winner of the group that includes England, Iran, the USA and Wales.
In 2002, Senegal finished second in their group and then defeated Sweden in the round of 16.