The Bees went into half-time 3-1 down after a quick-fire Marvin Sordell brace and a free-kick from Cauley Woodrow, despite having taken a 10th minute lead through Sergi Canos.
Brentford dominated much of the second-half and fought back to win the game 5-3 thanks to goals from Lasse Vibe (2), another from Canos and one from Jota.
Smith felt that his side were comfortable even at 3-1 down, and was pleased to have been proved right in his decision not to make changes at half-time.
“I thought that we started the game really well and took a deserved lead,” he said.
“I thought we had control of the football and then poor marking from two throw-ins, which led to two corners, then their set-piece routines and poor marking again in the box and you find yourself behind in a game that you are very comfortable in.
“Goals can change mindsets, it certainly changed ours, and we gave a stupid free-kick away on the edge of our box, Dan (Bentley) gets beaten from a free-kick that he should probably save on his side.
“You get in at half-time and it is very easy to make changes straight away but we had clear heads at the time and we knew that we had conceded three goals from set-pieces but we were relatively comfortable in the game. What we needed to do was up our energy levels and our movement of the ball and we did that really well.”
The result sees Brentford remain in 14th place in the league, while Saturday’s results have seen the Brewers drop to 21st, just a point above the relegation zone.