Celtic FC came from a goal behind to beat HJK Helsinki 2-1 in the first leg of their UEFA Champions League third round qualifier in Glasgow.

Rasmus Schüller opened the scoring for the visitors early in the second half but two goals in six minutes from Gary Hooper and Charlie Mulgrew gave Celtic a slender advantage to take into the return leg.

Clear-cut chances were at a premium in the first period. An instinctive half-volley from Joe Ledley, which brought a smart save from Ville Wallén in the HJK goal, and Joel Perovuo's strike from range were the only efforts on goal before the break.

The Finnish champions are already halfway through the domestic campaign and their match sharpness showed. They stunned the home crowd with the opening goal two minutes after the restart when Schüller tucked in the rebound after his first effort was saved by Forster.

Stung into action, Neil Lennon's side hit back. Kris Commons' strike hit a post, and on 54 minutes Celtic were level as Georgios Samaras' deep cross from the left was swept in by Hooper.

The home side had found their rhythm and seven minutes later Mulgrew nodded the Hoops ahead from a Commons corner. Wallen's fingertips prevented Scott Brown from adding a third, leaving the tie delicately poised ahead of Wednesday's return leg in Helsinki.