Polish striker Patryk Klimala scored his first goal for Celtic as Neil Lennon's side drew 1-1 with Nice in France last night.
He came off the bench to rescue a share of the spoils in their opening fixture of the Veolia Trophy at Groupama Stadium in Lyon.
This was Celtic's first competitive action for four months but they more than held their own against the French side in opening half an hour.
But on 38 minutes, Nice broke the deadlock; Danish striker, Kasper Dolberg getting free in the box and shooting past Scott Bain from close range.
Ryan Christie was a constant threat for the Scottish champions, shooting wide soon after the restart and forcing Walter Benitez into a good save when he got on the end of James Forrest's cross
With an hour gone, Lennon changed his entire starting XI and it paid dividends as Klimala bagged the equaliser in the 73rd minute, closing down the keeper to rob him of the ball before rolling it home.
Next up for Celtic is tomorrow's clash with Olympique Lyonnais, who lost 2-0 to Rangers last night.
An organised performance showcased both the Gers' defensive discipline and impressive counter-attacking quality.
A first half own goal from Marcelo and a Ianis Hagi drive gave the Ibrox men a commanding advantage before Ryan Kent's 39th minute red card changed the pattern of the game, but they showed great grit to hold on for the victory.
Lyon pressed forward in the last 10 minutes, throwing on superstars Memphis Depay and Moussa Dembele but it was to no avail against a brilliantly organised rearguard.