Celtic scored four goals in a quick 12-minute burst in the first half to easily beat St Johnstone and advance into the Scottish Gas Scottish Cup final.
The defending champions avenged their recent loss in Perth by defeating St Johnstone 5-0 and earning a spot in the final against Aberdeen on May 24 at Hampden Park.
With just one point needed in their last five matches to secure the William Hill Premiership title, Celtic are now on the verge of achieving a treble under Brendan Rodgers, facing the same team they beat in 2017 to claim their first treble. This would be the club's ninth treble and sixth in nine seasons.
Captain Callum McGregor opened the scoring in the 34th minute before assisting Daizen Maeda for the first of his two goals in the first half, sandwiched between Adam Idah's tap-in. Jota came off the bench to complete the scoring in the second half.
Rodgers stuck with the same lineup that scored five goals against Kilmarnock, making no changes after the defeat to St Johnstone.
Newcomer Idah was given a start, with Rodgers defending his professionalism after a video surfaced on social media showing him unwell during a night out earlier in the week.
The match was dominated by Celtic from the beginning, with James Forrest creating chances, McGregor, Arne Engels, and Maeda testing the opposition goalkeeper with long-range shots.
St Johnstone manager Simo Valakari's team contained Celtic's attacks initially but played a role in the first goal. Alistair Johnston capitalized on a defensive error to set up McGregor for the opener.
McGregor then assisted Maeda to double the lead, before Idah and Maeda added two more goals before halftime.
The second half saw missed opportunities for Idah and a disallowed goal for St Johnstone after a VAR review.
Jota sealed the victory for Celtic with a goal, while St Johnstone introduced debutant Uche Ikpeazu late in the game.