Not from the Swansea natives, of course. They had just seen their team claim a thrilling 3-2 win over Arsenal that took them up into the top half of the table, a full nine points clear of the bottom three with more than half of the season gone.
No, the ire was all generated by the visitors, who were sent packing back across the Severn with their tails between their legs and a second consecutive league defeat upon which to ruminate.
A week that began with Thierry Henry's heroic return to Arsenal by scoring the winner against Leeds on his 'second debut' for the Gunners ended with the striker exchanging words with a visiting fan following a defeat which leaves the Gunners in fifth place, four points behind Chelsea and that much-coveted final Champions League spot.
As the Gunners' players went to applaud the visiting fans after the final whistle Henry, 34, took exception to one fan's withering critique of his new/old team-mates.
In the verbal set-to Henry showed all the big-talking bravado he has learned in order to survive on the mean streets of Brooklyn, making a 'yapping' gesture with his hand and invited the fan to continue the frank discussion and free exchange of ideas on the pitch.
"No matter what, you should always support the team," said the man who left the club he captained for Barcelona in 2007 to the man who had travelled to a different country to watch him play.
But it wasn't just Henry and at least one disgruntled supporter who were in a funk following the defeat.
Arsenal manager Arsene Wenger already had the look of the town weirdo sat at a bus stop during the game as the 62-year-old sported his puffer jacket and trainers alone at one end of the away bench while his coaching staff were all congregated at the other.
However, rather than shouting incomprehensibly at passers-by for no good reason, Wenger did at least manage to direct his well-articulated annoyance at the assembled media after the match.
The main source of his displeasure was the penalty which led to Scott Sinclair's first-half equaliser. Aaron Ramsey - who had a particularly terrible time playing in the country he captains - was unfortunate to be penalised for tripping Nathan Dyer as the Swansea winger did a pirouette inside the box, but referee Michael Oliver could be forgiven for seeing a foul in his one and only look at the incident. Not by Wenger, though.
"Swansea played well but the game was decided by some strange decisions," Wenger said. "The first one was the referee who gave a penalty that was a complete imagination and was a good dive. Well done to the player who did it."
In fairness, Wenger did also offer forth praise to Swansea and the job done there by manager Brendan Rodgers, and well he might.
Perhaps on paper the result was not quite so extraordinary — Swansea had the joint-best defensive record at home going into the game (shipping just four goals), while Arsenal have now conceded the most goals (25) on the road in the league.
But what makes yesterday's win so noteworthy is that exactly nine years previously to the day they were bottom of the entire Football League while Arsenal were sat top of the Premier League table. The club was in financial turmoil and only avoided relegation to the Conference on the final day of the season. Now they are in the top half of the top flight in a brand new stadium, on course to stay up comfortably and by doing so on their terms.
Rodgers has not compromised the stylish, possession football that won them promotion via the play-offs last term. If anything, he has augmented it.
A new footballing philosophy that was started by Roberto Martinez almost five years ago and maintained by Paulo Sousa has been refined by Rodgers to such a degree that — as it stands today — the Swans' average pass completion rate for the season is 85.2%, the sixth-highest of any team across Europe's major leagues.
Striker Danny Graham — who scored the winner on Sunday just 45 seconds after Theo Walcott's equaliser — and goalkeeper Michel Vorm are the only summer signings Rodgers made upon going up who are regulars in the first team, and Vorm was only introduced after previous number one Dorus de Vries did one on a free transfer to Wolves.
And the January loan signing of Gylfi Sigurdsson - who built a burgeoning reputation with some stunning goals at Reading before moving to Hoffenheim — paid instant dividends when the debutant set up Graham for the winner just 16 seconds after play restarted following Walcott's strike. Bagging the Icelandic midfielder could prove to be the coup of this particular transfer window.
But it was the British contingent of Swansea's team that was the backbone of their victory. Welsh defender Ashley Williams was a commanding presence at the back while compatriot Joe Allen was the lynchpin of so many of his team's training ground triangles that gave Arsenal the runaround.
As for the all-English front three of Graham, Sinclair and Dyer, Rodgers reckons that Fabio Capello will have liked what he saw from his seat.
"He (Capello) would have been surprised at the level they played at," Rodgers said. "The front three were a massive threat all afternoon.
"Nathan scored a terrific goal and it was a wonderful finish from Danny Graham, and I'm sure it gave him something to think about. The advantage we have is that our players play a style that if they stepped up to international level it would be no surprise to them.
"Players at unfashionable clubs are questioned technically, but they have proved they can play at that level."
This result is sure to have an impact on the fight for Champions League places, and there will be much hand-wringing and many questions raised about Arsenal's future in the days to come no doubt.
But the last word should go to Rodgers: "It was a wonderful victory and performance from us. I'm very proud of the players and it's a great day for the people and the city of Swansea."
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QUOTE OF THE DAY: "I saw that as well and I think it's one of those maybe mischief-making Sunday-morning-prior-to-an-early-kick-off lead stories. From my point of view, there's certainly no suggestion that we are thinking in those terms. He (Barton) is captain of the club, I have re-iterated that this week. Joey is a quality player and we are looking to bring quality in, not to get those type of players out of the building." — New Queens Park Rangers manager Mark Hughes refutes reports that he is looking to get rid of club captain Joey Barton, who was suspended when QPR lost 1-0 at Newcastle in Hughes's first game in charge. Sunday papers making mischief? Never!
FEE OF THE DAY: £1.65 million — the fee earned by agent Manuel Salamanca Ferrer for negotiating the deal which took Ruben Rochina to Blackburn Rovers last January. Not bad work if you can get it, considering Barcelona received just £370,000 for the player.
FOREIGN VIEW: "We are making great strides. It was important to beat AC Milan, the first game against the big sides to go in our favour, so I'm satisfied. Lately we're playing well. We have rediscovered our energy and also the enthusiasm to do well. The Scudetto? As I said from the first day, I'm not speaking about it by choice." — Internazionale manager Claudio Ranieri plays down talk of joining the title race after he led Inter to a 1-0 win over Milan, the team's sixth-straight win. In 13 derbies as a manager in Italy, Ranieri has never lost, winning nine and drawing four.
COMING UP: Highlights of all the weekend's Premier League action are online now. If you're in a hurry, then check out the 90-second round-up of all the goals, or just the top five strikes if you really are pushed for time.
Later today we'll be bringing you our Team of the Week, Paul Parker's latest blog and also the latest despatch from the continent by Pitchside Europe.
Then later this evening it's a clash between top and bottom in the Premier League: follow live coverage of Wigan Athletic v Manchester City at 19:45.