Celtic failed in their quest to make it three Scottish Premiership wins in a row after drawing a blank against Steven MacLean's St Johnstone.
Brendan Rodgers men dropped their first points of the campaign as a resolute performance from the Saints saw the Perth side waltz off with a share of the spoils after a 0-0 draw.
The Northern Irishman and his charges were jeered by sections of the Celtic fans at the end as they took their customary bow.
Despite making four changes from the side that suffered a shock defeat last weekend to Kilmarnock in the League Cup, there was no backlash as the hosts failed to hit the target for the second week running.
Swedish centre-back Gustaf Lagerbielke made his first Parkhead start as did Korean wideman Yang.
Canadian right-back Alistair Johnston made his welcome return to the first-team fold after recovering from an ankle injury.
It was Danish under-21 midfielder Matt O'Riley was denied by inspired goalkeeping from St Johnstone shot-stopper Dimitar Mitov on three separate occasions.
However, in a carbon copy of last week's showing Celtic didn't really look like breaking the deadlock in a game that was typified by its slow tempo.
Whilst Celtic dominated both in terms of possession and territorially it was MacLean's outfit who could have stolen all three points on the counter as Joe Hart was called into action twice in the second half to save the day for the champions.
READ MORE: Brendan Rodgers on the Green Brigade and Celtic's 'slow tempo'
In truth, Celtic lacked the guile and the craft to break St Johnstone down and Rodgers even admitted that they did not deserve to win the game.
The next stop for Celtic is Ibrox and a rejuvenated Rangers side under Michael Beale who moved to within a point of the league leaders after a convincing 2-0 win over Ross County at Dingwall.
Rodgers faces a huge week both on and off the field as the transfer window ticks down.
The Celtic boss has made no secret of the fact that he wishes to bolster his squad before the trip to Govan and time is of the essence.
Join Tony Haggerty and Ryan McGinlay in the video below as they give their post-match reaction to the goalless stalemate.
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