Stanley Eguma claimed Lobi Stars were awarded a controversial penalty after Austin Ogunye's injury-time winner from the spot saw Rivers United bow 3-2 at Aper Aku Stadium.
Ogunye's equaliser ensured a 2-2 draw in the 69 minutes before his late winner came from the spot for Lobi, with the tactician accusing referee Folusho Ajayi of bias officiating.
And Eguma feels the late goal from the penalty that condemned his side to their sixth Nigeria Professional Football League defeat was 'hard to take' and he demands a review.
"I wasn't surprised any longer when she [referee Folusho Ajayi] pointed to the spot," Eguma told Goal.
"She awarded the penalty after my defender headed the ball away from the box. I challenge anybody to watch that video and see for themselves that it was not a penalty.
"I must say that even the fans of Lobi Stars protested it as no penalty. But the referee has awarded it as a penalty and It is hard to take.
"It is unfortunate that our league is still witnessing the anomaly. It is important that this is corrected for us to have fairness in our league.
"It very necessary for more fairness to determine the best representatives for continental competitions and winners of the league. It is really embarrassing."
The defeat saw Rivers United drop to 14th with 17 points from 13 games and they would face struggling Heartland at the Dan Anyiam Stadium on Sunday, April 1.