Is this the best Champions League group stage ever? Probably. And not just because of Celtic, though there was something uniquely stirring about their victory over Barcelona. For one thing it showed how the true greatness of the Glasgow club resides not in tired old Old Firm flim-flam but in a proud European tradition.
There is the 1967 European Cup victory, of course, which is still grievously under-rated compared to Manchester United's breakthrough the following year.
In 1970, Celtic cleared the champions of Portugal, Italy and England out of their way before falling at the final hurdle to Feyenoord. Their run to the 2003 UEFA Cup final, under Martin O'Neill, was an extraordinary one as they beat, among others, Liverpool and Blackburn Rovers at a time when the superiority of the Premier League to its Scottish equivalent was taken as read, before narrowly losing to an FC Porto side good enough to win the Champions League the following year under Jose Mourinho.
And just five years ago, Celtic, with our own Darren O'Dea at centre-back, forced an AC Milan team, who would go on to win the Champions League, into extra-time in the first knockout round before succumbing 1-0 on aggregate. Celtic have always been at their best when freed by European concerns from the spite and triviality of the Old Firm rivalry. Actually, so have Rangers.
The victory was made all the sweeter by the identity of the winning goalscorer. Tony Watt is 18, he was purchased from Airdrie United for the princely sum of £90,000 last year and, most importantly, he's Scottish. Watt's goal, and the huge contributions on the night of Charlie Mulgrew and Kris Commons, came at a time when the land of Hughie Gallacher, Jim Baxter, Denis Law and Kenny Dalglish is at a historically low ebb.
Last week's news that the national team had dropped to 70th in the world rankings, behind Uzbekistan, Haiti, the Cape Verde Islands and the Central African Republic seemed to confirm that Scotland simply doesn't produce good footballers anymore. Enter Celtic, and Tony Watt, riding over the hill like the Seventh Cavalry. Which is good news for anyone who cares about the huge amount Scotland has given to football in these islands.
But it's not just Celtic who've been turning this year's topsy-turvy competition into Tales of the Unexpected. Who'd have thought that Manchester City, Premier League champions, wouldn't have won a single one of their first four games and would be on the brink of an elimination which can only be avoided by the most unlikely results since Henry Kissinger won the Nobel Peace Prize and I passed Home Economics in the Leaving Cert?
Real Madrid and Borussia Dortmund were always going to prove tricky obstacles for City but surely nobody foresaw Mancini's money men taking just one point from six against an Ajax side who, like Celtic, have suddenly awoken from their European torpor to pay fitting tribute to a glorious tradition. This is an Ajax team in the classic mould, something emphasised by the presence of excellent left-back Daley Blind whose father Danny was an outstanding defender on the last side from the club to win the European Cup, in 1994.
Yet the team which most resembles that previous Ajax outfit is actually Borussia Dortmund, who have outclassed Real Madrid at home and away and City away, even if a moment of genius from Mesut Ozil and a moment of refereeing madness conspired to deny them victory late in two of those matches. Dortmund have been exhilarating to an extent which has made them replace Barcelona as the team you most like watching for aesthetic reasons. Inspired by Marco Reus (23) and Mario Gotze (20), they seem to be suggesting that the footballing as well as the economic future is German.
Everywhere you look in this year's competition there's something breathtaking. Victor Moses' Drogba-impersonating last-gasp winner for Chelsea against Shaktar Donetsk definitely came into this category because without it the reigning champions would probably have ended up losing out in their mighty three-cornered struggle with the Ukrainians and a resurgent Juventus.
Arsenal's fortunes swung the other way. Had they held on to the 2-0 lead their best European performance in many a moon had built them at Schalke, they'd be as good as through. The subsequent 2-2 draw shouldn't be fatal but the Gunners might need to get a result at Olympiakos in the final round. And if that sounds simple enough, you haven't been paying attention. Because in this season's Champions League, anything can happen and it probably will.
The bare statistics might show, for example, that things have been straightforward for Manchester United with four wins from four games qualifying them already. But the reality is that United twice looked dead and buried against Sporting Braga before contriving a pair of remarkable comebacks.
No team stands head and shoulders above its rivals in any group this season and this general tightening up has benefited several relative minnows who've performed well above expectations. Malaga may come from mighty La Liga but few would have expected them to do well in their first ever Champions League campaign and only their third ever of European football. It's only two years since they escaped relegation by a single point yet they've left both AC Milan and Zenit St Petersburg choking in their wake and currently boast the best defensive record and the second best goal difference in the competition.
The story of Belarusian champions BATE Borisov is even more remarkable. BATE's home stadium holds a little over 5,000 (they have to travel to Minsk to play their European games), their league is rated not far above the League of Ireland in the UEFA co-efficient and their team is composed almost exclusively of players from Belarus, a country whose one win out of four in the current World Cup qualifying campaign is pretty much par for the course. Yet they're still battling with both Bayern Munich and Valencia for a place in the knockout rounds.
In five of the eight groups, every team still has a chance to get through; in the others, there's a fierce three-way battle still going on. Celtic's win the other night guarantees them nothing -- they may
have to be Lisbon Lions again in their visit to Benfica to make sure of qualification.
It's worth pointing out that this is not in any way normal. Two seasons ago we went into the last round of the games with the qualifiers from seven of the eight groups having already been decided. The only suspense lay in the question of whether Arsenal would get the point they needed from a home game against Partizan Belgrade. Be still, my racing heart.
Normally there's a futile feel about this elongated process which ends up with the top two seeds making it comfortably through anyway. You watch the group stages out of duty rather than enthusiasm.
The early demise of the two Manchester clubs last season livened up things a bit but this year has surely gone beyond the expectations of the most hyperbolic UEFA PR man. Two seasons ago, Barcelona and Real Madrid looked a cut above everyone else. Now they've perceptibly drifted back towards the pack. After all, had it not been for Jordi Alba's 94th-minute heartbreaker in the Nou Camp, Celtic would have taken four points out of six against the Tiki Taka men. Last year's finalists have already lost to Donetsk and Borisov.
Then again it was last year's finalists who showed that, right now, you don't need to be a super team to win the Champions League. A modicum of talent, a lot of hard work, a steel nerve and a bit of luck could take you a long way.
That's why there's probably eight or maybe even more teams, who think they have a shot at winning this season's Champions League. Even 66/1 shots AC Milan and Valencia won't regard the mission as entirely impossible.
And that's why this is the best Champions League group stage ever. Not just probably but definitely. So far that is. But it's probably going to get better still.