The football championship exploded into life on Saturday and Kildare proved how close there are to being a very good team when dumping one of the favourites out of the competition.
It was a week that began with Kildare putting it up to the GAA authorities by refusing to travel to Croke Park after the GAA moved the game from Newbridge.
Cian O'Neill and Kildare made their position very clear that it was St Conleth's Park or nowhere.
Croke Park quoted health and safety issues but in the end, those issues were somehow addressed and David won the battle with Goliath.
The biggest battle, of course, was always going to be the game itself.
But a home game is a huge advantage and Cian O'Neill set up his team mentally and they produced a really terrific display.
The Newbridge pitch is an old-style provincial ground, shorter than most and a lot narrower. The crowd are practically on the pitch so there is a claustrophobic atmosphere for the players and that can be off-putting if you haven't experienced it before.
This Kildare team is full of big, strong, athletic players who are well capable of winning their own ball and also breaking tackles and releasing the ball.
They were rarely caught in possession and used the foot pass to great effect, particularly in the opening quarter when they raced into a five point lead.
I was very impressed with their calmness throughout the game and despite having to play in scorching conditions and almost 80 minutes of football, they continued to do the right things right to the final whistle.
Cian O'Neill has come in for a lot of criticism over the last twelve months and some of it is probably justified. But a lot of the things that were said were completely over the top. O'Neill is a good guy and someone who knows his job very well.
He works as hard as any other manager, as do the Kildare players, and on Saturday they got everything spot on collectively.
The start of the game was always going to be important and Kildare dominated from the throw.
A fully deserved five-point lead after 17 minutes had the crowd sensing a major upset but Mayo are no ordinary team and they have this incredible quality that keeps them battling.
That quality enabled them to go in ahead at the break after some excellent football.
I think most people would have thought at that stage that Mayo would 'do a Mayo' in the second half and do enough to get through this tricky tie.
They sneaked two points in front midway through the second period but it was Kildare who powered home.
O'Neill and his management team made the crucial changes at the correct times as David Slattery, Chris Healy, Niall Kelly and Eamonn Callaghan came off the bench and made telling contributions to their team's great win.
On the other hand, I felt the Mayo replacements were surprising and made very little impact.
Mayo needed changes to the full-forward line but instead brought defenders on for defenders.
In the end, they were unable to stop Kildare once they smelled the finishing line.
It has been a very tough year for Mayo football and this defeat will pr obably see a change of management for next season and a player or two calling time on their careers.
It would be foolish to write them off but this defeat will be hard to recover from.
I can see a lot of changes for next season in terms of personal and the panel probably needs an injection of young players.
The current group has been severely scarred, in a football sense, and they are now further away from winning an All-Ireland than ever before.
Kildare, on the other hand, are now just one win away from the Super Eights and based on yesterday's performance, I don't think they will fear any team in the other side of the draw.
If they did manage to get into the last eight, they would be entitled to one home game and I would fancy them against most teams at the Newbridge venue.
It was great to see so many Kildare supporters on the pitch yesterday, basking in the sunshine and the victory. Cian O'Neill and his players will go back training this week with a spring in their step.
It is another quick turnaround for them so the training will be light this week, with the emphasis on recovery and the challenges that next weekend's game will pose.
I enjoy watching a team that have their backs against the wall and come out and deliver a winning performance.
Kildare are back and if they can play like they did last Saturday, they will be very hard to beat.