Nigerian champions Remo Stars were in devastating form as they thrashed US Zilimadjou of Comoros 4-0 on Sunday night.
The Sky Blue Stars scored twice in the first half through Leonard Ngenge and Ebuka Anthony.
Malian striker Adama Goita and Samson Olasupo added two more goals for the Ikenne club after the break.
The second leg of the CAF Champions League preliminary round tie will take place at the Moshood Abiola Sports Arena, Abeokuta, on Friday.
Remo Stars are now on course to face South African champions Mamelodi Sundowns in the second round.
The Sky Blue Stars failed to reach the group stage of the competition in their previous two attempts.
