One false move and you suspected the tears might start.
As a jubilant and visibly emotional Russell Martin unwrapped what he'd just seen, he cut the figure of a man with an entire city on his shoulders. A man bursting with pride at giving his supporters a day that they will never forget.
"It means so much to everyone," he said. "We all watched the supporters leaving the stadium on the buses earlier, and we watched a video that had been put together by the analysts and the media team.
"It had messages from supporters and members of staff about what this meant to them, and I think once we had watched that we knew we had to come here and win." You can read his comments in full here.
Swansea City's 4-0 demolition of their biggest rivals will go down in history as one of the all-time great South Wales derby performances. Swans fans will probably be talking about it for years to come.
In contrast, this defeat will have left a deep cavernous scar in the capital. The torching of 110 years of history certainly compounds Cardiff woe, but even in isolation, this is a result that many will be unable to forgive.
In many ways, this was tougher to process for Cardiff fans than the defeat back in October. Cardiff are a much better side than the one that were hammered back then. But this was just as comprehensive and doubly disastrous. The fact no-one really saw it coming will only make it all the more gut-wrenching.
Mick McCarthy was sacked six days after that previous drubbing. Indeed, a heavy derby defeat is managerial cyanide at the best of times, and the pressure will be on Steve Morison to now muster up an acceptable response.
Morison has built up plenty of credit on the back of an encouraging few months in charge. He was clearly keen to take a step back from this derby-day disaster and look at the bigger picture.
"Obviously, we all want to win this game for the magnitude of it and how big it was. And I'm in charge when we've had the first double done against us. It's a worse defeat than we had earlier in the season, but the goal was to stay in the Championship so that's what I'm going to focus on." You can read his comments in full here.
While it's an assessment that is undeniably true, it's also probably torn a hole into some of the goodwill Morison has built up with the fans in recent weeks. At times like this, supporters don't want the bright side of things. In fact, there is no bright side. For Cardiff fans, the sun has expanded, swallowed up the earth and darkness is all that remains. To even suggest a focus on positives is, in the eyes of fans, to convey a lack of understanding of the situation.
All fans want to know is that the team they pay good money to go and watch is hurting as much as they are. Something similar to what Morison side after the 3-2 defeat in the Bristol City Severnside derby would have sufficed.
"It's got to hurt more," he said at the time. "It's got to come from within.
"People will always look at team selection or tactics, the reality is if you don't do the job you're asked to do or employed to do by the football club then you're going to get beat."
Some might, and indeed do, argue that Bristol City is a bigger game for Cardiff, although let's remember the Robins have also done the double over the Bluebirds this season, so there's little comfort to be found there either. In any case, there's no such conversation around Swansea. Cardiff is the only derby that counts.
It is, in many ways, the be all and end all game that matters far more than any other. Until Cardiff show some grasp of that reality, and mirror that level of passion, this is a fixture that could well continue to inflict pain.
We can talk about tactics and team selection all we like. But when watching Saturday's game, there was an inescapable fundamental reality; Swansea simply wanted it more. On derby day, where the form book can so often go out the window, desire alone can sometimes be enough to see you over the line.
As Morison himself acknowledged, too many Cardiff players didn't seem to be up for the occasion. Joel Bagan, so confident and full of vigour in recent weeks, shied back into his shell. Tommy Doyle and Joe Ralls succumbed to passenger status in midfield, and Jordan Hugill fluffed his lines on the rare occasions Cardiff did manage to step into the spotlight.
In contrast, Swansea oozed composure and class on the ball, keeping the Cardiff press at arm's length all afternoon. Flynn Downes ran the show in the middle of the park, while Jamie Paterson and Michael Obafemi will be in the nightmares of that Cardiff defence for many years to come. Even Obafemi's controversial celebration, whatever you may think of it, showed an understanding of the culture around this fixture.
Martin certainly deserves credit for what was a near-perfect gameplan, but that burning desire in the bellies of each and every one of those Swans players clearly took them up to another level on the day - a level Cardiff never showed any chance of matching.
It's clear this meant more to Swansea than it did to Cardiff. One only has to take a look at the respective build-ups from the two sides.
Swansea were keen to put fans at the heart of their preview content, with one piece featuring a young season ticket holder and the importance of beating your closest rivals. "I am with Swansea through thick and thin," he wrote. "Through high and lows, triumphs and disappointments, they will always be my club. I feel tremendous pride in my city and club."
In contrast, if you were to examine Cardiff's social channels this week, you'd be forgiven for wondering if there actually was a derby match this weekend. There's only so much excitement to be gained from watching Steven Caulker's header or Michael Chopra's last-minute winner for the gazillionth time. There was, overall, precious little to really gee up fans, or much in the way of acknowledgement that the club cares in the same way the supporters do.
Morison himself, despite acknowledging the 'magnitude' of this fixture, admitted that the the build-up felt like 'just another game', before seemingly suggesting that the lack of a derby double was just as significant as the 12-year winless run at QPR.
Just hours later, Martin was seemingly taking a very different tone. "I feel a real responsibility from everyone that’s here," he said.
"You look from the outside and think it’s a great football club, where it is and what it means to people. We’re all quite superficial, because you don’t have an understanding of what really goes on behind the scenes, and when you get here, you understand it. So I feel a responsibility. People make it, whatever club you’re at. "
In isolation, a lot of these points are small and largely insignificant. But together, they create a narrative that is growing increasingly difficult to disprove - and should worry everyone in the capital. At the moment, and for whatever reason, Swansea, as a club, seem to fully understand the importance of this wonderful fixture in a way that Cardiff just, well, don't.
