South Sudan held Sudan to a goalless draw at the Cecafa Challenge Cup in Ethiopia's Bahir Dar stadium in the first match between the two nations since they split four years ago.
The result leaves Sudan with a single point after two matches while South Sudan, which seceded in July 2011 after gaining independence from their northern neighbours, have collected four points in Group C.
Guest side Malawi top the group with a maximum six points from two wins over Sudan and Djibouti. Defending champions Kenya lead Group B on four points, level with Burundi after the two teams drew 1-1 on Wednesday.
Former champions Uganda are third on three points after losing 0-2 to Kenya and crushing Zanzibar 4-1 on Tuesday. Thursday is rest day before the next round of matches on Friday.