The first leg match in Burundi ended goalless for Rangers to progress to the second round of the competition 2-0 on aggregate.
The home team bossed the game but both sides missed several clear-cut chances in front of an 8,000-strong crowd at the Nnamdi Azikiwe Stadium in Enugu.
Uche Oguchi opened scoring for the home team after only three minutes from the penalty spot after Seun Taro was brought down inside the box.
‘The Flying Antelopes’ doubled their advantage through a thunderbolt delivered by Efe Yarhere on 16 minutes.
Rangers could have increased their lead in the 72nd minute, but Sanusi Sani’s effort crashed against the crossbar and nine minutes later, substitute Alhaji Gero failed to get on the scoreboard when he was one-on-one with the Vital’O goalkeeper.
Goalkeeper Godwin Ayalogu ensured he kept a clean sheet when he saved a penalty in stoppage time after Yarhere pulled a Vital’O player down inside the vital area.