Ekeng came off the bench in the 62nd minute of the match, but fell to the ground seven minutes later and was immediately rushed to hospital.
The Cameroonian received CPR for 90 minutes, but he was eventually pronounced dead at the hospital.
Play bizarrely resumed after Ekeng's collapse as the game ended 3-3.
Ekeng started his professional career with Canon Yaounde and joined Le Mans in 2009 as he made the move to Europe.
He also wore the jerseys of Rodez, Lausanne Sport and Cordoba before signing for Dinamo at the start of 2016.