An early own goal from Stevie Hammell and a late headed second from William Gros gave Kilmarnock a win and three points that they scarcely deserved.
And Nicholl - standing in for Kenny Shiels who was serving a touchline ban - was honest in his assessment after his side took the win despite being pounded by Motherwell.
"We had a great start to the game and although we were lucky to get the own goal I thought here we go," said Nicholl.
"Then we did nothing except face waves of attacks from Motherwell when we just couldn't get the ball out of our own half.
"I said to the players at half-time that they didn't have a hope in hell of winning the game if they continued like that - and I'm sure they were sitting in the Motherwell dressing room wondering how they were 1-0 down at half-time, and I was asking how we were 1-0 ahead."
