Ivan Toney's penalty, swiftly followed by a fierce first-time strike from Emiliano Marcondes, secured a 2-0 win for Brentford in the Championship play-off final against Swansea City.
Brentford lost to Fulham at the same stage last year, Jansson's first with the club after leaving Bielsa's Leeds, which was promoted as champion and has this term enjoyed a spectacular return to the Premier League, finishing ninth.
But Jansson explained that what he learned from Bielsa played a pivotal role in Brentford ending a 74-year absence from the top flight.
"Last year a lot of Leeds fans was against me, this year so many Leeds fans have been with me and with Brentford, probably because they are already there and they wanted me to come and join them," Jansson said.
"I love Leeds, Brentford fans know I love Leeds, Leeds is one of the favourite clubs I have, of course I love Brentford as much, I'm so proud, I'm so happy, I could go home to Sweden and retire because this is what I've dreamt of for such a long time since I came to England, finally of course I will not go home, I will stay here and hopefully play Premier League football.
"I'm so thankful to Bielsa for what he gave me at Leeds, he gave me so much knowledge that I actually brought to Brentford and Brentford was so willing to listen to me and my ideas that I took from Bielsa.
"I thank him a lot because he's one of the best coaches in the world. People think mine and his relationship is not the best but it is, I'm so thankful to him."
Brentford scored 79 goals in the 46-game Championship season, the most in the division, increasing the tally for the campaign to 84 with its efforts in the play-offs.
There were scored 73 non-penalty goals across 49 matches, underperforming an xG of 74.4 but playing an expansive style of football reflective of what Jansson experienced at Leeds.
Toney was the talisman behind the Bees' promotion, his spot-kick taking him to 33 goals in a remarkable campaign. Twenty-two of those goals came from 135 non-penalty shots with an xG of 20.7.
Asked about what he could do in front of goal in the top tier, Toney replied: "I don't know, who knows what's to come?
"I'm a Premier League striker now and I can't wait to score goals in the Prem."