Ezenkosi looked promising and absorbed pressure from the home side, and they took the lead before the break. But their rock-solid defence cracked when it mattered most.
"I think we played well in the first half. But Celtic came back strongly in the second stanza," Sono tells KickOff.com.
"They got two chances and buried them, and that was it. Their first goal took the steam out of my players and the second one was a beauty.
"After those goals, Celtic totally changed the complexion of the game and attacked us from all angles. Their third goal was a killer punch. However, even when we were 3-1 down we still kept going at them. But we couldn't find any more goals.
"We were unfortunate to lose the match. We also had chances of our own, however, we failed to make them count. The difference between them and us is they took their chances well and we couldn't do the same," he adds.
Now Cosmos will forget about Wednesday's loss and focus on their Telkom Knockout match against Bidvest Wits at Sinaba Stadium on Sunday.
"We have to focus on both cup and League games. If we do well in the cup that will give the boys confidence going forward.
"But our main priority is the League. I hope all my players will be back for the weekend's game," he concludes.