The Gers went ahead on the fifth minute through Rosie Mcquillan and had a number of chances to add to the scoreline, but Forfar got back level with just 15 minutes remaining.
Emma Brownlie secured the three points with a free-kick on the 80th minute, but Vignal felt the game could have already been over given the earlier chances.
He said: “It is not the best performance from us but three points in the bag and it was a difficult game today we didn’t play so well but in the end we got the three points.
“We could have scored two or three goals in the first 15 minutes but this is where we need to improve.
“I said to the girls in the final third you need to be really aggressive in front of the goal so hopefully we will learn from this.
“I think we showed good character to come back and it was a really good free-kick from Emma, good composure on the ball and with her right-foot. That’s what I said you take your responsibility and that is what we need and she scores and we won so it is good.”
The victory follows on from last weekend’s league win against Stirling University, and Vignal feels confidence is growing as the squad head into an international break before the SSE Scottish Cup semi-final against Glasgow City in two weeks time.
He added: “It is good for confidence now as we look and prepare for the City game in two weeks.
“It will be a massive game a really strong game and I have got two weeks to prepare. Lisa [Martinez] will be away with the national team and we will give the girls two or three days off because they need to relax and there has been a big demand from me since July.
“We have a few injuries so we will see with Hannah Robertson and Brogan Hay next week we will check with the medical staff, the girls will have days off after Thursday night to go and see their family and enjoy the weekend and then we will start again properly on Monday to prepare for the City game.”