The Enugu side held on to their early goals to beat the club from Burundi who put up a good game at the Nnamdi Azikiwe Stadium
The first leg match in Bujumbura ended goalless for Rangers to progress to the second round of the competition 2-0 on aggregate.
Rangers will now play Angola side, Recreativo Libolo in the last round before the lucrative group stage of the Champions League.
The sparse crowd at the Nnamdi Azikiwe Stadium had hardly settled down to watch the game when Uche Oguchi opened scoring for the home team after only three minutes from the penalty spot.
Oluwaseun Taro was brought down inside the box and referee Hamoudi Djamel from Algeria wasted no time in awarding a penalty to the home side.
Efe Yarhere doubled the lead in the 16th minute with a ferocious shot off a free kick.
Vital'O settled down after the second goal and started playing well knowing that they needed to score to have any chance of qualifying.
But their greatest undoing was not been able to put the ball inside the net in spite of their excellent play in the midfield.
Rangers could have increased their lead in the 72nd minute, but Sanusi Sani’s effort crashed against the crossbar and nine minutes later, Flying Eagles Alhaji Gero failed to find the net when he came face to face with Bipfubusa Methode in goal for Vital'O.
Rangers were reduced to 10 men twelve minutes before the end of the match, after two central defenders, Ekene Iwuorie and Ousmane Sane were injured and pulled out and the technical crew had made the three mandatory changes.
Minutes before the end of the match, Chibuzor Madu pulled a Vital'O player for a penalty for the away side.
But Nzigamasado Steven hit the wood work to deny his club a goal in Enugu.
Chibuzor Madu told Goal.com that it was a hard fought game: "We did not expect that Vital'O will play the way they did, but I am happy we held on to win."