Three single goal victories had almost killed off the festive goodwill among the Celtic support despite watching their side start the new year unbeaten after 19 SPFL matches.
Nineteen minutes after Mulgrew found the net Kris Commons rifled a shot high into the net to complete the scoring following an Anthony Stokes strike and a header from Commons- his 50th Celtic goal in three years.
The return to form was welcomed by the fans with only the combination of the woodwork and some inspired goalkeeping from Marion Kello keeping the score down.
Without doubt the star of the show this season has been Commons who seems to have taken on extra responsibility with the team missing Gary Hooper and Victor Wanyama.
The former Derby County man cost just £300,000 when he arrived in Glasgow three years ago with Lennon in no doubt about the value and quality of his former Nottingham Forest team-mate.
“Kris’s goal return is fantastic and it would be interesting to see how many assists he’s had also,” his boss said.
“He is a player who I believe will get better because there are aspects of his game he can work on.
“At 30 years of age the penny drops but his goal return this season has been good and he’s so important for us.
“He has three, four, five good years still in him and is getting better.
“His vision is fantastic and the chip that hit the post would have been a contender for goal of the season but I’m sure he’ll acknowledge the contribution of Emilio Izaguirre and James Forrest for his goals.”