Lamptey saw his side take the lead as early as the third minute through Latif Blessing.
But Kotoko raced back to snatch victory with goals from Ahmed Adams, Dauda Mohammed and Amos Frimpong.
Lamptey questioned how his players allowed a winning position to slip by.
“Today’s game was one of the worst games in my career, right from the referee’s whistle things didn’t go well,” he said in a post-match conference.
“Disappointing. How can you surrender a 1-0 lead and lost 3-1. Terrible!”