The frustrating thing is that the Saints game plan worked for the first 20 minutes or so. Celtic were being frustrated and their fans were quiet. Then it all went very, very wrong.
Midway through the half a nice Celtic move seemed to have broken down when a Saints defender managed to get a foot in. However, the ball broke to Scott Brown and he easily slid it past Chris Smith for the opener.
If that was unlucky, the second was down right shocking from Smith. A long ball from Mark Wilson seemed to be heading for Scott McDonald when Smith decided that he was getting to it. There wasn't a chance in hell of that, even if he'd started his run five seconds earlier, and the Aussie lifted it over Smith into the net.
Saints chances of getting back into it were slim, especially as the likes of David van Zanten, Mark Corcoran and Hugh Murray were all unwilling to shoot when given decent chances.
4-5-1 at home is all very well when you're level, or even a goal down. 2-0 down it's not much use, but there were no changes. Then, just as it looked as if Billy Mehmet (not much use but the best we have) was about to arrive, Celtic went 3-0 up when Jan Vennegoor of Hesselink nodded a corner past Smith to finish things off.
So, you're 3-0 down at home with one up. You're about to bring a striker on, who do you take off? Spot on - you take off the other striker. Unbelievably, that's what MacPherson did - with Kean trotting off to be replaced by Mehmet.
Any slim hope that this wonder change would change things disappeared minutes later when a Riordan cross/shot was diverted past Smith by Miranda. It should be pointed out the attack came from a corner... a Saints corner.
MacPherson then realised that a second striker might not be a bad idea and replaced Gary Mason (god knows why him, Brady was far, far worse) with Birchall and moved Corcoran up front.
Celtic added a fifth when some static defending from Saints allowed Stephen McManus to force the ball home after a scramble in the box. The goal of the day coming a minute later - Miranda showing exactly what happens when someone actually bothers to shoot by firing past Artur Boruc from 25 yards.
Sadly, Hugh Murray had to limp off after that - meaning he may miss his testimonial on Thursday - and left us with the exciting prospect of Richard Brittain and Brady in midfield. On the plus side, Corcoran did decide to have a shot and forced Boruc into a save.
Miranda was lucky to avoid a red card in the final few minutes when Brown indulged in some showboating, earning him a shove from the Argentinian. Fortunately, the referee - who let Celtic players off with some shocking tackles - only booked him.
A terrible day, and some people and players need to have a good look at themselves. Brady and Reid for starters do not seem good enough for this level. And as for the tactics - why leave your new signing on the bench? Why stay with one up when you're 2-0 down? Why make a like for like change when you're 3-0 down?
Only Gus MacPherson knows the answer to these - and he also knows why we still don't have another striker and are left with dross like Kean and Mehmet to pin our hopes on.