Jeong snatches Union late draw at Stuttgart in Bundesliga
Germany winger Chris Fuehrich's goal had Stuttgart on course for third spot but the South Korean's late equaliser leaves the German Cup holders in fourth, a point ahead of fifth-placed RB Leipzig.
Unfancied Union are now unbeaten since early December, a run of five matches, and sit eighth, five points behind the European placings.
After a first-half with few chances for either side, Fuehrich put the hosts in front just before the hour mark.
Stuttgart defender Ramon Hendriks charged forward before finding Fuehrich, who hit a low shot just inside the left-hand post.
Germany midfielder Angelo Stiller had a golden chance to double Stuttgart's lead with 10 minutes remaining but blasted wide with the goal beckoning and only Union goalie Frederik Ronnow to beat.
The miss came back to haunt the hosts almost immediately when former Stuttgart forward Jeong sliced his shot into the top corner on the 83rd-minute mark.
Jeong, who did not celebrate his goal, had a chance to steal the match against his former employers in the dying moments, but his strike was well saved by Stuttgart's Alexander Nuebel.
Later on Sunday, Freiburg travel to struggling Augsburg.