And his second-half strike helped the Ibrox club maintain their winning record in SPFL League One while keeping alive their hopes of a "Perfect Season".
But the Gers centre-half was still downhearted after the eventful Glebe Park outing.
Because Brechin took advantage of a disastrous first half performance by the visiting defence and netted three times.
The French-Tunisian player has become a cult hero with the Light Blues support thanks to his goalscoring exploits.
However, the 26-year-old still prides himself, above all else, on his ability to stop opposition teams scoring. And Mohsni is determined there will be no repeat of the slip-ups in the future - starting with the game against East Fife in Methil this Saturday.
He said. "I have been enjoying good form and have been pleased to contribute some goals for the team.
"I try to get up the pitch whenever I can and finish off moves if it is possible. I used to play in midfield so it is natural to me.
"I have had a good start at Rangers and the team has had a good start to the league. We have a strong team and we want to keep our run going.
"We want to win every game that we play in and hopefully we can do that. But we have to defend well in every game in order to do that.
"Sure, I like to get up the park and score goals. But I am a defender and my top priority has to be stopping the other team from scoring whenever we play."
Mohsni was as surprised as anybody in the ground at the weekend at the goals that Rangers let in during the first 45 minutes. For the Glasgow giants had conceded just twice - against Brechin and Arbroath in games at Ibrox - in the eight matches they had played in the third tier before that.
But Graham Hay, Jonny Brown and Alan Trouten met with minimal resistance as they fired Ray McKinnon's team into a commanding 3-1 lead at half-time.
The torrential rain the game was played in and the two-week break from competitive football that preceded it may have been responsible for the woeful display.
Mohsni certainly feels he has gelled well with club captain Lee McCulloch in the heart of the Rangers rearguard.
And he is hopeful the backline will function far better in their league match at New Bayview on Saturday against opponents who beat Dunfermline at East End Park last weekend.
"The manager has put me together in the team at the back along with Lee and I am enjoying playing there with him," he said.
"Lee is a very experienced player and it is straighforward for me to play with him. He communicates well and helps you through the matches.
"He lets me go up the park whenever there is a chance for me to do that. He covers for me at the back when I go forward.
"He gives me confidence. He makes me think the back line is very strong. I hope I can continue playing with him in the team."
Mohsni added: "Of course, we have to keep playing well and getting results in every game in order to stay in the team. There is competition for places at the club.
"But that is a good thing. It helps you work hard in training and maintain a high standard on the park. We have good players in every position.
"We should win every game that we play in the league if we play to our very best. But, of course, the away games can be difficult."
After winning their opening nine league games and surging 10 points clear of Stenhousemuir in SPFL League One, talk of a "Perfect Season" has intensified.
Few teams in any sport have gone throughout an entire league campaign without suffering a draw or a defeat.
But the superior spending power Rangers have over their rivals - the majority of whom are part-time - has led to speculation they may be able to achieve the feat.
Mohsni, though, knows that Ally McCoist's team will come unstuck if they defend like they did in Angus again during the 2013/14 campaign.
And he revealed that nobody in the Rangers dressing room is targeting what would be an historic accomplishment.
"We have not talked about it at all," he said. "We just try to work hard in training and concentrate on the next game.
"We have found our games away from home difficult this season. The Forfar match, for example, was very hard. The wind made it difficult for us.
"That is what we have to expect whenever we go away. We have to play well or we will struggle."