The midfielder claimed the all-important 69th-minute strike, deflecting a Romaine Sawyers shot from outside the box to wrong-foot City’s substitute goalkeeper Ivan Lucic.
“I think the ball went in off Maxime’s backside,” smiled Smith. “Sometimes you need a bit of luck to record victories in the Championship and he will want the goal, even though it was a fantastic strike by Romaine.
“It was a tough night for us. The game was end-to-end with chances for both sides.
“A draw would have been a fair result, but we managed to get over the line. Strangely, both team’s main goalscorers couldn’t finish on the night.
“Scott Hogan for us and Tammy Abraham for them had numerous chances, mainly due to mistakes, and couldn’t capitalise.
“There were a couple of good saves on both sides. The first half was really open, not by design but because of the mentality both teams adopt.”
The only surprise was that Colin’s goal was the only goalscoring opportunity taken in a game which saw both defences in generous mood.
Abraham alone might have scored five and, while Brentford were also guilty of poor finishing, City head coach Lee Johnson was a frustrated man.
He said: “I’m very disappointed by the result but okay with the performance because on another night we would have scored three or four goals.
“The game has hinged on us not taking our chances. Tammy played well and got into some good areas, but he just couldn’t finish.
“He is a young player and will come again. It’s a time to put an arm around him, not take out a big stick.
“I was much more concerned with how we played at Huddersfield on Saturday. Tonight it seemed as though one of us had run over a black cat.
“The ground was a bit quiet and we now need to stick together and rally the troops for another home game on Saturday.”
City lost goalkeeper Frank Fielding with a rib injury after 31 minutes and gave a Championship debut to 21-year-old Lucic, who did well.
Fielding had already saved twice one-on-one against Hogan, whose pace had the home centre-backs chasing shadows at times.
Abraham’s best chances came in the second half when he tried to beat advancing goalkeeper Daniel Bentley with a delicate chip only to put his effort wide and clipped the top of the crossbar when he should have found the target.
Bobby Reid also had opportunities for the hosts, who will look back on the game as one that was allowed to slip away.