Even this St Johnstone team has its limits.
As well drilled as Callum Davidson has got his tight squad, and as brilliant as their collective form has been, taking a point or more off Celtic with nine players out proved to be a bridge too far.
The big news was the Perth starting line-up and the fact that the ongoing Covid-19 crisis is biting deeper rather than loosening its grip.
There was a debut in goal for emergency loan signing Bobby Zlamal, Charlie Gilmour made his first start in midfield and James Brown was part of a reshaped backline.
The hope will be that players start to return in time for Saturday’s fifth place Premiership decider against Livingston.
The Scottish Cup final is, of course, the big prize and the match Davidson will want to have everybody fit and available for, but going into the Hampden Park clash against Hibs knowing that European football has been secured would be a huge pre-May 22 boost.
On that front, this result hasn’t done any damage.
With Livingston losing 3-0 to Rangers, Saints remain ahead of the side they defeated in the Betfred Cup final on goal difference and will only need to draw the match between the two Euro hopefuls at McDiarmid Park on Saturday.
It was the first time Shaun Rooney has been deployed as the right-sided centre-back for a while and his replacement at wing-back, James Brown, made a Rooney-esque run and cross that caused a bit of mild panic in the Celtic box.
Brown sent over the sort of ball which was just too far out for a goalkeeper to come and claim but behind the centre-backs.
Craig Conway did his best to finish it off at the back post but couldn’t get there in time.
The early momentum was all with Saints.
Brown was taking up more attacking positions in the first 10 minutes than he did in the whole game against Hibs recently and he would have been disappointed that he didn’t keep a glancing header from a Glenn Middleton cross on target.
Saints had built a solid foundation but by the midway point of the first half that platform was in pieces following the concession of two goals in less than 60 seconds.
Davidson and his players were furious at the opener. They felt the ball Zlamal picked up just inside his 18-yard line shouldn’t have been deemed as a pass-back.
From there, though, David Turnbull was clinical, drilling a low shot under the wall that didn’t leave the grass and found the stand-in keeper’s bottom right corner.
The second was a classy goal, one seen all too infrequently this season if you’re a Celtic fan.
Scott Brown played a diagonal over Rooney’s head and Odsonne Edouard’s sublime first touch took it through the defender’s legs and from there Zlamal was helpless to keep out the deft finish.
To get back into this contest the visitors really needed a swift response and a Chris Kane effort from an under-hit Jonjoe Kenny back-pass provided the opportunity for just that. Vasilis Barkas made a decent save but Kane should have scored.
Celtic didn’t look in a mood to settle for just two goals in Brown’s last match at Parkhead and they pinned Saints back in the opening stages of the second half.
Most of their attacks were coming down the Hoops’ right and Zlamal made a fine save to deny Ryan Christie from that side of the box and then got himself into position to save from Edouard shortly after.
Saints had a glorious opportunity to reduce Celtic’s lead when the ball broke nicely for Conway just inside the box. Barkas was beaten but the former Dundee United man opted to steer his right foot shot rather than go for power and youngster Adam Montgomery cleared from just in front of the goal line.
At the other end Zlamal made a superb block at the feet of Edouard and from the rebound Mohamed Elyounoussi struck his shot into his grounded team-mate and the ball looped over the bar.
There was an even more spectacular save with just over 15 minutes left when he got his fingers to a fierce Greg Taylor 20-yarder that had top corner goal written all over it.
With Saints’ priority now protecting their goal difference over Livi, Celtic scored a third when Kristoffer Ajer’s deflected shot sailed over a helpless Zlamal and a fourth from young substitute Karamoko Dembele.
The scoring stopped there, making it the Perth side’s heaviest defeat of the season.
On this occasion, though, what is happening off the pitch will be of more significance and concern.
