Winless in their previous six games and suffering the worst slump of form in recent memory, Rangers had been given little chance of taking anything other than a severe beating ahead of this crunch Champions League clash with Porto that would go a long way in deciding the fate of the European prospects of each club as well as the future of their under-fire managers.
It seemed ill-fortune was set to visit McLeish and his men once more this evening when their heroic early resistance was finally punctured just short of the hour mark when Lisandro put Porto in front but an unexpected twist in the tale still lay in wait.
Only seven minutes remained when Ross McCormack seized upon an inviting knock down from fellow substitute Chris Burke to thrash a fierce shot beyond the hitherto untested Vitor Baia to earn Rangers a precious point.
The result – coupled with Inter Milan’s win over Artmedia Bratislava in the other Group H game – guarantees Rangers some form of European football in the New Year, with the tantalising possibility of a place in the last 16 of the Champions League still dangling in front of McLeish ahead of the final group games in two weeks’ time.
Porto, who can no longer progress in the competition, could yet have a vital role to play when they travel to Slovakia to meet Artmedia in their final group game, probably still wondering how they did not put Rangers to the sword after dominating possession for the bulk of the 90 minutes.
McLeish had sent his side out in a defensive 4-1-4-1 with Franny Jeffers as the lone striker and they predictably spent most of the game chasing their more illustrious opponents all around the park.
While the Light Blues were industrious and diligent, Porto oozed panache and verve. Needing a victory to retain any ambition of reaching the last 16, Co Adriaanse’s side pressed forward from the first whistle and within 60 seconds the lively Quaresma had skipped around Alex Rae to angle in a testing drive that Ronald Waterreus did well to hold.
It was an early indication of how the rest of the 90 minutes would unfold with Jeffers and Baia virtual spectators as play raged on at the other end of the field albeit often with no end product.
Bosingwa, in particular, was enjoying a productive shift down Porto’s right flank and from one enticing centre Lisandro should have done better than head over after manoeuvring himself in front of Marvin Andrews to meet the cross.
Rangers stemmed the early flow but, missing the rampaging runs of the injured Dado Prso, offered next to nothing as an attacking force.
At the other end Quaresma, when he wasn’t falling over, was giving Fernando Ricksen a torrid time down the Porto left flank with a series of beguiling feints and twists.
In one particular cameo he somehow managed to squeeze between his tormented marker and Hamed Namouchi with an outrageous shimmy although his shot was weak and straight into the side netting.
With Rangers’ rigid formation looking increasingly impenetrable, the half concluded with Porto well on top but without having truly tested Waterreus.
Adriaanse’s response was to withdraw a centre-half – Pedro Emanuel – and pitch in another striker in the form of Hugo Almeida.
Three minutes on and Almeida could have made himself an instant hero when he fastened on to Quaresma’s inviting left-wing cross only to slice it horrendously wide like a high-handicap golfer trying to hack his way out of the rough.
It was another let-off for Rangers but respite would be brief as Porto’s territorial superiority eventually yielded them a goal just before the hour mark.
Bosingwa was the creator with a sumptuous cross from wide on the right and Lisandro atoned for his earlier miss by threading a header high into the net.
It was a crushing blow to a Rangers defence that had defended stoically and resolutely up until that point and, with his original game plan now blown out the water, McLeish reacted almost immediately by sending on Steven Thompson to give Jeffers some company up front.
It made little immediate difference although Rangers did eventually create their first chance of the match on 69 minutes, Barry Ferguson wastefully blazing a right-foot shot high over the crossbar when composure was called for.
McCormack and then Burke followed Thompson from the bench onto the pitch and the pair would combine to dramatic effect when Rangers drew level seven minutes from time.
McCormack started the move with a pass wide to Ricksen whose cross appeared to be drifting harmlessly out for a goal kick before Burke stretched every sinew to nod the ball across the face of the goal.
From around six yards McCormack needed no second invitation to thunder a fierce shot beyond Baia to send the visiting supporters into raptures.
After the celebrations had died down, Rangers still had to face a nervy six minutes as Porto surged forward looking for a late winner.
A miraculous double block by Waterreus somehow kept out Lisandro’s late attempts as Rangers held on to record a memorable result that guarantees them European football after Christmas.
PORTO (4-3-3): 99 Baia; 12 Bosingwa, 4 Emanuel (Almeida 46), 14 Pepe, 21 Peixoto; 8 Lucho, 18 Assuncao, 20 Diego (Alves 64); 17 Jorginho, 11 Lisandro, 7 Quaresma
Subs not used: da Silva, Costa, Ibson, McCarthy, Ivanildo
Booked: Quaresma (84)
RANGERS (4-1-4-1): 25 Waterreus; 2 Ricksen, 14 Kyrgiakos, 5 Andrews, 24 Murray; 7 Hemdani; 31 Namouchi, 8 A Rae (Thompson 62), 6 Ferguson, 26 Lovenkrands (Burke 78); 21 Jeffers (McCormack 75)
Subs not used: Klos, Malcolm, Pierre-Fanfan, Hutton
Booked: Hemdani (58), Murray (62), Ferguson (84)