The despair on Braga goalkeeper Beto's face after Jackson Martinez smashed in Porto's second at the death said it all. It was a mix of exasperation and tiredness that spoke volumes of what had been an intense encounter between the northern rivals. It was little wonder that not one Braga or Porto player stopped to speak to speak to journalists in the post-match media area and that the champions' coach Vitor Pereira described himself as "emotionally worn out" by the night's events. "If I wasn't exuberant (on the touchline)," he said, "I'm sorry."
This Porto, though, are not for breaking. They could not have showcased their durability any more clearly than they did against a potential title rival on Sunday, scoring twice in stoppage time to bend a hitherto goalless game in their favour. There's no doubt about it - this was a genuine test for Pereira's men. It was the first of a trilogy in fact, with Porto returning to the Estadio AXA for a re-run in the Taca de Portugal on Friday before the final match of the Champions League group stage on Tuesday next week, away to Paris Saint-Germain.
We have suspected for some weeks that this team could be worthy of joining the pantheon of great Porto sides of recent years, but this is the sort of mini-series that will give a better idea as to the validity of that feeling. There is an intuition and mental fortitude to the current crop that simply wasn't there in the last campaign.
On paper, last season's Porto should have been that side - even minus the departed Radamel Falcao - following a record summer outlay on players in 2011, but they were listless and anaemic far too often. They managed to retain their title through a combination of a few big performances, the lack of other credible candidates and Benfica's post-Christmas flounder.
When creator and goalscorer-in-chief Hulk left for Zenit St Petersburg in September, few would have backed Porto to assume an upward trajectory, but that's exactly what's happened. In typically well-prepared style, they already had a successor anointed in their ranks, with the brilliant young Colombian James Rodriguez starting on the left with licence to cut in, and the reliable Silvestre Varela on the left and able to swap wings with him.
Yet the change in Porto appears to be a more spiritual than technical one. Pereira carried the air of a browbeaten supply teacher during his debut season at the helm, lacking the charisma or certainty of his erstwhile boss Andre Villas-Boas, who he had been promoted to replace.
Pereira spoke in press conferences like his team played on the pitch: without inspiration and lacking personality. It was quite a jolt from the inexorable form of Villas-Boas' year. When midfield mastermind Joao Moutinho said after a typically frustrating European night against APOEL that "we're not managing to click as a team", the future looked grim for Pereira. Even post-title win, many thought he might be quietly shifted aside, though president Jorge Nuno Pinto da Costa publically - and emphatically - rejected the idea.
Today, Pereira seems to have grown into the job. There is a commanding aura around him on and off the pitch. Best of all from his perspective, his Porto side has its own personality, rather than being just a re-tread of the AVB era one. The shape, a loose 4-3-3, is the same, but that was thus in the Jesualdo Ferreira era too. Just as Villas-Boas made his own tweaks, Pereira has now had the confidence to make his.
Porto don't go for the jugular with quite such a devil-may-care abandon as Villas-Boas' team did. They are relentless in a different way, grinding the opposition down with their passing rhythm before suddenly upping the pace in the final third via their wide men. They attempted the same tactics last season, with limited success.
A few key personnel adjustments have helped. The most obvious one is the reintegration of Lucho Gonzalez, who arrived back at the club from Marseille in January. Now 31, his metronomic passing sets the tone in midfield - and given that he was no gazelle in the first place, his advancing years promise to be no problem. After a slow first season at the club, Steven Defour's value is becoming clear, as he can fill in for either Lucho or defensive sentinel Fernando, adding dynamism to the role in both cases. Up front, Jackson has shown his muscle is complemented by considerable composure. His goal against Braga was his ninth in nine Liga games.
Still, the real driving force is Moutinho. It is almost as if he has taken confidence from his failed move to Tottenham - after all, both Porto and the player were more than aware of his value as they tried to hustle Spurs' offer in terms of transfer fee and wages up and up. Astonishingly, his high personal standards of performance have been lifted even further since. The 25-year-old has even started weighing in with a few goals, following shooting tuition from club legend Maniche.
The team's shift in approach and confidence levels has been most apparent in the Champions League, where they disappointed last season in a weak group. It will be interesting to see how Porto match up in the return against PSG, a game from which they need just a point to win the group. Their bossing of Carlo Ancelotti's side at the Dragao was laudable, and a similar performance in the French capital would bear out the confidence in the squad that they can go a long way in Europe.
By then, spring will bear the usual rumours linking the stars with moving on. Moutinho, James and Jackson will doubtless be on the menu again. Manchester United and Juventus had scouts at the AXA once more on Sunday to watch James give his side the lead, just as they had for the Champions League match against Dinamo Zagreb earlier in the week.
Accordingly, Porto's remit will be to seize the moment, as it always is in the transient world of Portuguese football. This team might just have the belief in itself to do so.