The Bhoys take a one-goal lead into the second-leg of their Champions League third-round qualifier after a hard-fought victory over the Swedish side on Wednesday night
The forward nodded home the final 15 minutes to give his side a crucial advantage and keep the Bhoys' fans dreaming of another memorable campaign in Europe's top club competition.
The home side started the match positively with Anthony Stokes volleying just wide after a headed flick-on by strike partner Georgios Samaras.
The Swedish champions organised their defence well after the initial chance for Celtic and frustrated the home side when they had possession.
It was not until the 20th minute that the first goal-scoring chance came, when Celtic winger James Forrest hit the crossbar with a volley from a cross from opposite winger Commons.
Moments later, the Bhoys had the ball in the back of the net after another cross from Commons was met by a confident finish from Stokes, but he was flagged offside.
That seemed to tempt the visitors to attack more frequently, which resulted in captain and former Southampton midfielder Anders Svensson rattling the crossbar with a ferocious effort from 25 yards, before meeting a Stefan Ishizaki corner with a header which went just over.
Celtic defender Efe Ambrose should have put Neil Lennon's side in front shortly before half-time; but the Nigerian should have done better with a header after yet another fine delivery from Commons.
The hosts started the second half on top again, with Samaras forcing a save from Kevin Stuhr-Ellegaard in the Elfsborg goal shortly after the restart. The home side kept possession well despite failing to create much in terms of goal-scoring opportunities.
However, their hard work paid off in the 76th minute when left-back Emilio Izaguirre crossed for Commons, who confidently headed past Stuhr-Ellegaard in the Elfsborg goal.
The home side pushed for a second late on and came close to doubling their advantage after Samaras had a header cleared off the line by Andreas Klarstrem, but Lennon will be pleased to take a clean sheet and a lead to Sweden.