Noonan steps forward to act as Kenny's bodyguard - but it'll be the final time
While a recent convert to Irish politics might view them as two close allies, in reality they are fierce old enemies. Their battle for the party leadership in 2001 was bitter, and when Mr Noonan failed to hand the future Taoiseach a frontbench job afterwards, colleagues suggested the Limerick TD "was shafting somebody just for the sake of it".
Mr Kenny is reported to have told Mr Noonan he was making a mistake - sending out the wrong signal at a time when he should be about healing and unity.
A little over a year later, Mr Kenny took the leadership after a disastrous general election result that saw Mr Noonan's star plummet.
But in sharp contrast, Mr Kenny brought his rival into his tent - and for the last six years has trusted him to manage the fragile economy.
Now their political survival is intertwined to the point where Mr Noonan is fighting to save the man he once argued wasn't good enough for his own frontbench.
It's the not the first time in recent years that the 73-year-old has stepped forward to act as bodyguard for the embattled Taoiseach - but it may well be the last.
He began the offensive a week ago at the height of the Sgt Maurice McCabe scandal.
With Mr Kenny facing severe criticism for his handling of the crisis from the media, the Opposition and the backbenches, the weekly Fine Gael parliamentary party meeting was set to be fraught.
The Taoiseach opened proceedings by outlining that mistakes had been made but the party needed to band together to fend off a motion of no confidence from Sinn Féin.
Mr Noonan was the third person to address the meeting, following party chairman Martin Heydon, who said: "United we stand, divided we fall."
One observer said the Finance Minister was "very strong", adding: "The old dog came out fighting."
He told TDs and senators the country was on the way to full employment and that young people were returning home after years of emigration.
"We have a good story to tell," he said, in a bid to help colleagues see past the fog of public anger.
However, what followed is likely to have surprised him. Once upon a time, not too long ago, a rallying call from Mr Noonan would have calmed the room.
Instead, Leo Varadkar, Simon Coveney and Simon Harris all took to their feet to issue a coded ultimatum to Mr Kenny.
The party could not be "election ready" while Mr Kenny remained at the helm.
The new generation had grown weary of the public mood, felt embarrassed by the chaos at the heart of Government and were tired of the Taoiseach's attempts to long-finger his retirement.
Sources say the waning of Mr Noonan's influence was a clear sign that the second-coming was nearing an end.
"There was a time when Michael Noonan would make a speech like that and everybody would jump on board with his message," said a source.
But the flame hasn't gone out completely yet and Mr Noonan yesterday adopted a new approach by sitting down one to one with backbenchers in a bid to take the heat out of calls for Mr Kenny's resignation.
"Are we really going to throw a Taoiseach out of office," he asked people who have only known Mr Kenny as leader of the party.
He accurately predicted that Mr Kenny would be considered a "lame duck" if he was to give an exit date before travelling to the US for St Patrick's Day. And Mr Noonan urged his colleagues to give Mr Kenny time to ensure an orderly transition.
To some degree, this may have worked and the threatened motion of no confidence is off the table for now.
But other ministers argued last night that the ball game is different now.
Mr Kenny will be allowed go to Washington but what comes next will be decided by the younger members of the Cabinet and the party.
They see Mr Noonan as a vested interest whose political career is inextricably linked to the Taoiseach's.
Fine Gael is moving on.