There is a strange dichotomy at work in Scottish football. On the domestic front, Celtic have set a pace in the league that has placed pressure on Rangers under which they have buckled.

Meanwhile, it was impossible to see the desperate failure of Neil Lennon’s men last night as entirely unrelated to the heroics of the Ibrox men in Braga the previous evening.

The remarkable home and away victories over Portugal’s in-form team by Steven Gerrard’s men – the first time a Scottish club had won both legs in the knock-out stages of European competition since Celtic beat Blackburn Rovers in 2002 during their run to Uefa Cup final – did more than book them a place in the Europa League last 16. It set down a gauntlet to Celtic, who have never gone so deep into this competition since it was revamped. Ultimately, they could only respond in abject fashion.

Celtic boss Neil Lennon cuts a dejected figure at full-time. Picture: SNS

Rangers’ progress led to all sorts of excitable chatter about the two Glasgow behemoths meeting in the competition next month. It always seemed dangerous talk when Celtic still had an awkward return leg against a Copenhagen side who had the Scottish champions on their uppers in the second half of the clubs’ 1-1 draw in Denmark last week.

In recent days many hosannas have been rightfully lavished on Lennon for his incredible year in charge. Glossed over amid all the commendations for his re-energising of the team he took over in the hours after Brendan Rodgers’ flit to Leicester City was the aberration of the Champions League qualifying exit at home to Cluj: a nutty 4-3 defeat that followed the hard work supposedly having been done courtesy of a 1-1 away draw.

Even as Celtic made first-half chances that should have put them well on course to seal the tie, their disjointed, skittish nature began to stir uncomfortable memories of that August evening. Long before, indeed, Michael Santos capitalised on a horrible error from Jozo Simunovic to put Copenhagen in front in the tie with 39 minutes remaining.

Even the 82nd minute award of a VAR-adjudged penalty coolly converted by Odsonne Edouard couldn’t prevent a Cluj-style calamity and the loss of two further goals in the closing minutes. The final seconds were played out in a near-deserted stadium as the 3-1 defeat exposed all the strange deficiencies that have undone Celtic in knock-out European ties against teams with a fraction of their resources in the past six years. In that sense, last night could be added to the roll call of ignominy that covers defeats by Maribor, Malmo, AEK Athens and Cluj. Three different managers – Ronny Deila, Rodgers and Lennon – having these black marks against their names.

Such eliminations represent precisely the sort of setbacks that Gerrard has suffered on the home front but avoided on the continental stage. A real curiosity that defies simple explanation.

Why Celtic's defeat highlights curious contrast between champions and rivals Rangers