Fabianski spent seven years at Arsenal before joining Swansea last summer and received applause from both sets of fans at the Emirates Stadium.
Swansea are now just two points behind sixth-placed Tottenham and the 30-year-old insisted the pursuit of Europa League football was the main motivator for his impressive display.
“I spent seven years here and I have loads of friends here so to play against them was a strange experience, and sometimes it even felt like a training game,” Fabianski said.
“It was tricky. You never know how you are going to feel until you experience something. It was strange arriving at the ground and seeing all the people, but there was a game to play and I had to be focused.”
Fabianski added: “I am past that frustration (at Arsenal). It has been a long time since I left Arsenal so I am just enjoying my position at the moment at Swansea.
“I am very happy with my decision to come here and I am really proud of the team’s performance.”