This was arguably Sunderland's best performance of the season so far and for sure, it was one in which they would take a lot of pride.
But it tells you everything about the control the Black Cats currently seem to have that even in the immediate aftermath of this win, there was a focus on the bigger picture and the next challenges quickly moving into view.
Part of that is perhaps due to the realities of behind-closed-doors football. Last time Sunderland achieved a positive result at Fratton Park a raucous away end swayed to the prospect of a return to Wembley, a play-off final spot secured.
Nathan Broadhead explains why he opted to join Wigan Athletic after Sunderland interest
Sunderland AFC transfer gossip: Cats agree to sign transfer listed ex-Wigan Athletic defender - reports
Alex Neil explains what happened with Nathan Broadhead, Sunderland, Wigan Athletic and Everton in transfer verdict
Supercomputer predicts Sunderland, Middlesbrough and Sheffield United's final Championship position
'Bottle job move' - Sunderland fans offer opinions on Nathan Broadhead's move to Wigan Athletic
Kevin Phillips was on punditry duty then as he was last night. In 2019 he would barely have been able to hear himself think as the red-and-white army serenaded him. There could be no repeat scenes this time around but those watching on Wearside could be forgiven for feeling a similar sense of excitement.
Lee Johnson spoke of a 'steely focus' he had sensed in his players right through the day and right now they carry the air of a team whose ambition is to be a major contender for a top-two spot over the next eleven games.
This was the biggest test of their credentials yet and the result was emphatic.
Without a doubt, there were one or two key moments where luck was on their side. Jordan Jones produced a wonderful chip to double his side's lead in the second half but a minute earlier there had looked to be a clear foul from Aiden McGeady, left unpunished by the referee.
Kenny Jackett also felt his side should have had a penalty after that and the Portsmouth boss was no doubt left frustrated that John Marquis could not make more of a gilt-edged chance late in the first half as he was sprung clear on goal.
What he could not challenge, however, was that his side were beaten by the better team.
Sunderland were again more ruthless in both boxes than their opponent and all over the pitch they played with more energy and purpose.
Johnson afterwards insisted that as always, in victory as in defeat, there was much to improve.
Nothing has been achieved yet, all the hard work is still to be done and all Sunderland can do is stay grounded and focus on the process.
All of that is true and that steely focus of his squad told you that they have bought into this message completely. It was still a significant moment for the Head Coach nevertheless.
His starting XI was striking in its intent and number of attacking players. Yet whereas before this system and some of its combinations have left the balance of the side looking a little off, here the control was almost total.
Johnson has spoken before of the challenges of getting Jones and Aiden McGeady into the same team, and at the moment he is managing that without leaving his team defensively vulnerable.
All of that was built on the platform of another two excellent defensive performances.
Jackett had reverted to a 4-4-2 as he looked to turn around his team's ailing form and early on it was clear what Sunderland could expect.
The home side would go long quickly and early, and it would be a stern examination of Dion Sanderson and Luke O'Nien's credentials.
Sanderson was excellent and O'Nien quite simply outstanding.
Sunderland were prepared to be direct, too, when they needed to relieve some pressure. The difference through the first half at least was that they were finding their target more often, O'Brien and Wyke pulling into the channels and holding the ball up well.
When Portsmouth went to Marquis and Ellis Harrison both were often isolated and easily dealt with by Sunderland's ever-impressive defensive pair.
There was not a great deal in the game through that first half but Charlie Wyke's superb header meant the away side were both content and in control.
Key to that, despite the attacking formation and side, was that in the heart of midfield they were also excelling.
Josh Scowen was energetic and effective in breaking up the play, while Carl Winchester delivered something of a breakthrough performance, always showing for the ball and making good decisions when he received it.
Johnson has said from day one that League Two was not his level and here you could see it.
From that platform the second half performance was just about faultless.
Sunderland looked vulnerable for a brief spell after Jones' goal, Portsmouth finally finding some urgency. The Black Cats had dropped into a back three and for a while it seemed to be inviting pressure.
Yet Johnson quickly sorted it, reverting to a 4-4-1-1. The Black Cats came through what was a brief spell unscathed and finished the game not just in control but as the greater attacking threat.
In a crucial game in the battle for promotion, their goalkeeper did not have to make a significant save.
That in one statistic tells you the control they had over this contest.
Johnson would not take too much praise after the game, saying that he had inherited a good team whose performances should have left them further up the table.
All the same, this is a side increasingly thriving in his style and the balance with which they are currently playing speaks to the way cohesion and understanding is building in his squad.
Sunderland have a tough run-in and as Johnson reminded everyone, they remain very much the challengers.
That steely focus of his side, however, tells you there is no one that they will fear right now.
This race for the top two has begun and make no mistake, Sunderland are right in it.