GAA: Welcome to the past. After a long summer of ordinary football, the importance of this championship is becoming clear. On a hot and edgy afternoon in Croke Park, the powerful sight of Kerry football in full flow once again filled the sky, eclipsing the northern lights and all other pretenders.

With a game revolving around the towering frame of Kieran Donaghy, who caused havoc in front of the Armagh goal, and the sheer, bloody-minded brilliance of the Ó Sé brothers, the Kingdom reaffirmed their superiority with a 3-15 to 1-13 victory against the hardest team of modern times. Joe Kernan will never say die but there was a sense Armagh's epic quest for a second All-Ireland reached an end this weekend. There were flashes of ruthless brilliance here but they were not the machine of old.

In the second quarter-final, Cork edged out Donegal, in what was a desperately close and poor encounter, to set up another all-Munster semi-final.

Just like that, the lights are out all over Ulster. For the first time in the history of the championship, there will be no county from the northern province in the All-Ireland semi-finals. That alone will be a cause for celebration for critics of the Ulster way, but in the years to come the realisation will dawn on everyone that Armagh, for all their confrontational bluster, were simply more exciting and more serious about Gaelic football than most counties. Gaelic games will not see their likes again.

In the past three years, there was something heroic and perhaps even mad about Armagh's obsession with another All-Ireland title, because they knew they had only so many years left.

The differences between Kerry and Armagh have often been analysed but the most obvious contrast was confirmed on Saturday. Armagh were a passing wonder; Kerry, though, are permanent.

What Kerry did on Saturday afternoon was a damning response by Jack O'Connor to the growing criticism of his regime within the county and a classic example of the peerless Kerry football tradition.

"A lot of criticism was directed at me but the only way to deal with it is on the pitch," said the Kerry manager afterwards. "I want to thank the lads for that."

It was an old-style Kerry performance, based on fearless attacking. Donaghy's reinvention as a full forward has been described as a homage to Eoin "Bomber" Liston, but if anything, the big Tralee man has proved that positions don't really matter anymore. Donaghy has had a sensational impact on the championship, and yesterday he gave Francie Bellew a torrid hour.

"What do you do with him?" mused Armagh's Oisín McConville afterwards. "They just seemed to hoof it but how to you mark him unless you have someone who's six-foot-six?"

The answer may be by meeting like with like. The best way to deal with a midfielder-turned-full-forward may be to use a midfielder as a full back.

Billy Morgan and Cork have two weeks to prepare for the high-flying Donaghy and a Kerry team who suddenly look in rude health. The Munster champions were not impressive in beating Donegal, who looked nervous and tentative throughout.

It was a poor game, brightened only by fine individual performances from Cork's Nicholas Murphy and Donegal's Karl Lacey. Ger Spillane knocked over a winning point for Cork deep into injury time.

Morgan acknowledged that Kerry would be favourites to win the semi-final, but as he smiled thinly on Saturday evening, there was the sense he was secretly relishing the prospect of another tilt at Kerry.

"Someone asked me recently what's progress. Well, we lost by what, 13 points last year? So if we keep them to 12 this year, that's progress," he said mischievously before hurrying off to catch the train, inscrutable as ever.