The former West Ham midfielder tapped home a delightful right-footed cross from fellow substitute Ryan Fraser having been on the pitch just six minutes.
Bournemouth now sit top of the Championship pile after the 1-0 win and Howe is hoping that Stanislas' class continues to shine through in the division.
He said: "I knew we needed to try and get some pace on the flanks and knowing the quality of the two we brought on we were in no doubt that would happen.
"Certain games require certain things and this game required an injection of pace on the flanks and I was really pleased for both that we got the goal by them teaming up.
"There are no easy games in this division we know that ourselves coming from league one we know each game is a battle and that is how it proved.
"Junior (Stanislas) has everything you want in a modern day wide man and I am very happy we have got him.
"I think he is the perfect age at 24 because he has had time to mature and I knew he would be hungry to play as he did not get much game time at Burnley last season.
"He assisted two goals during the week and scored today so I think his class is really showing."
The summer arrivals goal may have proved decisive by the game was far from one-sided with Brentford missing a host of chances.
In fact Mark Warburton's men could have been away and gone in the opening half with Andre Gray forcing Lee Camp into a smart save.
The former Luton also crashed the underside of the bar but Warburton was left to bemoan his sides' failure to take chances.
He said: "I thought we were very positive and I felt we dominated the last 30 minutes and the opening quarter and definitely deserved at least a point.
"We handled players like Matt Ritchie and Callum Wilson well and dealt with what they had to offer us and I don't think we will play many better footballing teams this season.
"But we have to learn that the margins in this division are tiny and you have to take your chances.
"I thought we lacked some quality in the final third in the second half but we had the right attitude and I think we still had enough chances to score two maybe three.
"We dominated the last half an hour and I think we deserved at least a draw today but Bournemouth are a team that we aim to learn from.
"Last season they had two heavy opening defeats in this division and they came back from that to finish the season really well."