Celtic slipped to a high-scoring defeat in their warm-up match against Rennes in Portugal.
Ange Postecoglou's side were out in Portugal training ahead of the return of domestic action.
Scottish football has been halted due to the World Cup but returns next week.
And Celtic prepared for a return to competitive action by taking on Rennes in a warm-up fixture after a week of training in Portugal.
It was the Ligue 1 side who would run out the victors with a 4-3 scoreline.
Celtic fell behind almost instantly in the match with Martin Terrier firing past Joe Hart from the near post within the first 60 seconds.
But Celtic did level things up in the 18th minute with Matt O'Riley getting on the scoresheet. The midfielder curled into the corner after finding space in the box.
Just two minutes later, however, and Rennes were back in front. Amine Gouiri slotted home after a Benjamin Bourigeaud through ball.
After 27 minutes, the French club extended their advantage as Lorenz Assignon smashed past Hart to doubled his side's lead.
Rennes then went out to make it four-one seven minutes from the break. Warmed Omari was on hand to volley past Hart as he was left unmarked in the centre of the box.
Celtic would rally before half-time however and claw back the deficit. Kyogo Furuhashi first pulled one back as he lobbed Dogan Alemdar in the Rennes goal.
And O'Riley scored his second to reduce the scoreline further just one minute from half time. He was afforded time on the edge of the box and sent a powerful drive past Alemdar.
After an exciting first half with end-to-end attacks it was a far more settled second period. Despite seven goals in the first 45 minutes there would be no more goals in the Portugal sun with Rennes running out narrow victors in the friendly fixture.
Celtic starting line-up: Hart, Ralston, Starfelt, Jenz, Taylor, Hatate, O'Riley, McGregor, Abada, Kyogo, Jota.
