Galway manager Brian Hanley hailed an 'incredible' start to their summer as the Electric Ireland All-Ireland minor title holders got their title defence off to a remarkable start.
Victory for Galway in the quarter-final group stage, their opening game of the Championship, looked all but certain when they led by a whopping 12 points close to half-time.
Yet in what was a repeat of last year's All-Ireland final, Kilkenny wiped that deficit out entirely by the 48th minute with a giant momentum swing occurring.
Ian Byrne was terrific for the young Cats with two second-half goals after his half-time introduction and he scored 2-2 in total.
Richie Mulrooney's side couldn't push on to take the lead though and it was Sean McDonagh's 50th minute goal for Galway which ultimately separated the sides at Croke Park.
It capped a strong game from McDonagh who top scored for Galway with 1-7 while Greg Thomas lit up the first-half with two goals.
Galway have another game left to play, against Clare, while Kilkenny are on the verge of an All-Ireland semi-final against Limerick despite the defeat.
"It was incredible, that would be the best word for it," said Galway manager Hanley, who praised his side's ability to dig deep again after relinquishing the 12-point lead.
"We have our values and our systems written up on the wall in our dressing-room. Those things can mean nothing to some people but they mean everything to us.
We worked savagely and showed responsibility, teamwork, communication, all the stuff you need in a game like that and it bore fruit for us in the last 15 minutes. That character came through. For their first day out this year, it was a credit to them.
Kilkenny manager Mulrooney described it as a 'win-win' game for his team too, despite ultimately slipping to a three-point loss, their second setback of the summer after losing the Leinster final to Wexford.
He was delighted with the show of character to turn an apparent lost cause into a genuine contest, as well as the fact that it's likely Kilkenny will reach the semi-finals.
Even a Galway loss to Clare next weekend, leaving all three teams on two points, could still send Kilkenny through to the last four on scoring difference.
"Even though it was a loss, you have to understand that I'm absolutely delighted because firstly, the comeback and the character we showed and the hurling we produced and the fact secondly that this group, which had very little expectation on it, has a great chance of being in an All-Ireland semi-final," said Mulrooney.
S McDonagh (1-7, 3 frees); G Thomas (2-2); G Lee, C Connaire (0-2 each); L Leen, T Killeen, C Molloy (0-1 each).
I Byrne (2-2, 1 free); B Drennan (0-6, 6 frees); T Clifford, P Blanchfield (0-2 each); C O'Sullivan, P McDonald, L Moore, B Wheeler (0-1 each).
M Egan; E Davoren, E Lawless, A Nolan; E Collins, I McGlynn, C Brennan; L Leen, O Slevin; T Killeen, S McDonagh, C Cunningham; G Lee, S Morgan, G Thomas.
A Connaire for Slevin (41); P Cummins for Lee (50); S O'Hanlon for Leen (53); R Howley for Collins (55); C Molloy for Killeen (58).
A Tallis; P McDonald, W Halpin, T Roche; B Reid, P Moylan, J Aylward; A Hickey, D Walsh; P Blanchfield, L Moore, J Doyle; B Drennan, T Clifford, C O'Sullivan.
I Byrne for Hickey (h/t); ZB Hammond for Walsh (h/t); B Wheeler for Doyle (59); S Doyle for Drennan (60).
T Walsh (Waterford).