Celtic are nine points clear again at the top of the Premiership after a relatively comfortable afternoon in Perth.
Celtic were ahead early and it was another nightmare for Andy Considine on his 600th senior appearance. Having conceded an own goal when the teams met back in October, he did it again when he diverted Kyogo Furuhashi's cross into his own net in nine minutes.
Then the Japanese star took advantage of another Considine blooper when the veteran defender allowed Jota's cross to go through his legs and Kyogo showed his predatory power with a swivel and strike from close range in 22 minutes.
Saints had actually had some decent moments in the first half and Drey Wright slammed a goal back three minutes later. But Aaron Mooy produced a superb lob finish seven minutes before half-time after being teed up by Kyogo.
Then in injury time after Considine was sent off for pulling back Oh Hyeon-gyu, David Turnbull grabbed a fourth with a low shot.
READ MORE: The Celtic key trait that stands them apart from Rangers and everybody else claims Michael Stewart
Here's three thing we learned at McDiarmid Park
Mooy is the Bhoy
Ange Postecoglou says he wants to learn the ambition of some of his key stars who are heading into the final year of their contracts.
Aaron Mooy is one of them and on current form, Postecoglou should be offering a pen to sign a new deal right now.
The Australian midfielder has been sensational since returning from the World Cup where he also played so well.
Mooy is bursting with confidence right now and that was so evident with a superb finish for Celtic's third goal.
But it's his passing and positioning that is so key to Celtic right now as he keeps Matt O'Riley out of the team
Kyogo predator in chief
There seems little doubt that the Japanese star is the best No9 in Scotland right now.
Furuhashi always plays on the edge of offside - indeed drifts beyond a lot before darting back - and that makes it so difficult for defenders.
However, there is ingenuity to his play too as he showed in his attempted pass which Considine diverted into the net and how he was involved in the build-up to Aaron Mooy's goal.
Maybe it is reaction to the signing of Oh from Korea but Kyogo is simply un-droppable in the Premiership right now and he scored his 21st goal of the season which was typical of his ruthlessness in the box
Not a lotta Jota
The Portuguese star did graze the top of the crossbar with a very well struck left foot shot after a super Celtic move in the second half.
But it was a largely frustrating day for Jota whose skills were undoubtedly not helped by the dire playing surface.
He gave away a few fouls too and did not hit the heights that the fans are so used to seeing.
Saints dealt with him pretty well overall - but they couldn't handle Kyogo
READ MORE
- Ange Postecoglou in Daizen Maeda 'menace' tag as Celtic boss hails Greg Taylor and Kyogo Furuhashi
- Joe Hart's four word Celtic send off to Oliver Abildgaard after transfer switch to Hellas Verona