Undav went on as substitute with the Germans a goal down.
They came back to secure their place in the last 32 of the World Cup.
Nadiem Amiri served up a wonderful curled delivery from the right for Undav to equalise with a controlled volley midway through the second half.
Adingra wasted an excellent position to put Ivory Coast back ahead when he took an extra touch having been released by Nicolas Pepe and was closed down.
Germany grabbed a dramatic winner in the fourth minute of stoppage time when Felix Nmecha passed into Undav, who controlled, turned and fired home in expert style to clinch a 2-1 success.
Undav has scored three goals in two games as sub in the tournament and would appear to now be pushing for a start.
He scored eight goals for Albion in league and cup but never established himself as a regular and left in the summer of 2023.
The Stuttgart striker now has seven goals in ten games for Germany.
Pascal Gross remained unused on the subs’ bench.