When Ricardo Carvalho strolled the length of Stamford Bridge to seal Chelsea's second successive title with their third goal against Manchester United in April, it was a gauge of their supremacy that a centre-back possessed the confidence and the class to dispose of their closest rivals so disdainfully.
It was equally emotional for Chelsea when their Portuguese defender headed in Frank Lampard's corner to secure a draw at Old Trafford, but the significance of his latest goal is yet to be determined.
In the short term, it restricts their deficit to Manchester United to a manageable three points, rather than the ominous six that was threatened by Louis Saha's opener. In the long term, it may ensure a closer title race with the league table making United marginal favourites.
What Carvalho did do, however, was to provide proof of Chelsea's battling qualities; proof of the spirit with which Jose Mourinho has imbued them; proof that, in a class of contrasting philosophies, theirs is equally admirable and while Wayne Rooney may consider them boring, they were equally capable of gaining ascendancy with a focus on the positive.
As Mourinho summed it up: 'In the first half, Man United were the best team. In the second half, Chelsea were the best team. They score in the first half because they were the best team and we score in the second half because Chelsea were the best team. That's obvious.'
For 45 minutes, Chelsea were outflanked. Ryan Giggs and Cristiano Ronaldo surged forward against their unprotected full-backs, exposing the chinks in Chelsea's tactics even if, conversely, incision was sometimes provided from runners coming in off the flanks.
The unselfish performances came from Michael Carrick and Paul Scholes, sublimating individual attacking ambition to sit deep and shield their defence from Michael Ballack and Frank Lampard. And while United had the upper hand, England past overcame England present as Scholes hassled and harried Lampard into ineffectiveness.
Indeed, it was no coincidence that Lampard was the man dispossessed for Saha's goal, before Giggs swiftly found Rooney and he, in turn, picked out Saha to bend his shot around Carvalho and past Carlo Cudicini.
Sir Alex Ferguson said: 'He was almost like a caged animal, dying to get to the game. He demonstrated an eagerness to eliminate the penalty miss from earlier in the week.'
It showed, incidentally that, unlike bureaucracy, football provides a capacity for redemption at the earliest opportunity. Saha, culpable for United's defeat to Celtic, returned to the scoresheet while Peter Kenyon, whose terribly-timed comments riled the home support to the extent that there was the rarity of abusive chants directed at a chief executive, has much to do to salvage his own reputation.
Riling Manchester United, he really should know, is not the cleverest move, regardless of which club will be biggest in 2014. But while Kenyon failed, Mourinho prospered.
Accommodating his best 11 players in his first-choice formation had proved elusive. After a half-time switch, he may have achieved it. For 45 minutes, Chelsea's outlet was Geremi, the right back. United's were the wingers, some 20 yards further forward.
The danger of United's emphasis on width was shown after the interval when Chelsea's dominance in the centre enabled them to power forward. But, paradoxically, that also came after the introduction of a genuine winger in Arjen Robben.
And Robben's effectiveness on the left was replicated on the opposite flank where Michael Essien became their fourth right back of their season. It doesn't quite rival Arsenal's eight left backs last season - though that was largely the result of injuries - but it's only November. Essien may prove the last though: the marauding Ghanaian was by far the most effective.
'In the second half, we showed our power,' commented Mourinho. They also showed their prowess at set pieces, though Ferguson was very much in a minority in not crediting Carvalho with the equaliser, saying: 'It was an own goal from Louis Saha, it just touched the top of his head. I think Edwin van der Sar had it covered.'
Perhaps. The third talking point involving Saha was his late withdrawal, along with Cristiano Ronaldo's. They appeared precautionary moves, but they are two players United can ill-afford to lose.
Ferguson's shortage of striking options shown by the presence of three defenders on the bench; Darren Fletcher and John O'Shea were hardly like-for-like replacements for Ronaldo and Saha, while Southend and Copenhagen have already exposed the weaknesses of United's supporting cast.
Chelsea, in contrast, enjoyed the luxury of introducing Robben and Joe Cole.
The former's arrival made the greater difference, aided by Mourinho's tactical switch. While there was a fire alarm in the early hours of the morning at the Chelsea hotel, the visitors may have got more of a jolt at half-time, courtesy of their manager. The different ways two Portuguese men, Mourinho and Carvalho, used their heads at Old Trafford could yet prove decisive in the title race.