O'Brien delighted as Corofin turn on style to drown Nemo
Corofin 2-19 Nemo Rangers 0-10
In a perfect sequence, Corofin have now won all three All-Ireland club finals they have contested by multiples of five, increasing the margin of victory each time by that amount.
It might be stretching it to aim for a 20-point win the next time they return because, for now, the ceiling for perfection from a club side on this stage looks like it has been reached.
It's an impossible one to gauge. In the near five-decade history of this competition there have been bigger wins, but surely never a better performance.
This was, after all, seven-time champions Nemo Rangers on the receiving end of a 15-point defeat; a team that dumped out the reigning champions Dr Crokes and then saw off many people's idea of their successors, Slaughtneil.
But that form line was in tatters from the opening minutes at Croke Park on Saturday as Corofin ripped through them with some of the most mesmerising teamwork ever produced by a club.
Quite often one-sided games like this can be a bore for the spectators, especially neutrals, but you couldn't help appreciate their play.
Annaghdown came close to dethroning them in a Galway semi-final and while they beat Mountbellew-Moylough convincingly in the final, they required extra-time to beat both St Brigid's and Castlebar Mitchels in Connacht, before surviving by a goal with 14 men against Moorefield in the All-Ireland semi-final. Concerns that some of their old pace had eroded was palpable.
However, Croke Park brought the best out of them in 1998 and 2015 and the place just electrified them again.
From those moments when Gary Sice cut through for an opening point that could have been a goal, and Liam Silke had cannoned a shot off an upright from an equally good position, Nemo were taking in water and soon their ship had capsized.
Like Dublin at inter-county level, it looked like Corofin were playing a different game at times. Except this was an All-Ireland final, where Dublin have yet to produce a comparative performance.
Watching them string passes together by hand and boot felt like something computer-generated; it was that precise.
To compound matters for Nemo, that flying start from Corofin was constructed into the wind at a time when the Munster champions should have been dominant and building a healthy lead to protect.
Instead they found themselves chasing shadows and starved of possession as Daithí Burke - restored to the starting team - and Ronan Steede dominated midfield, with Michael Farragher, another regular midfielder, coming out from his listed corner-forward position to make a devastating impact.
Everything Corofin did had purpose. Even at the back, pairing up Dylan Wall - who landed two points and is surely a target now for Kevin Walsh - with Nemo's Paul Kerrigan and Liam Silke against Luke Connolly, worked well. Connolly provided most resistance for Nemo, but he was only ever scratching the surface.
Sice followed up that early point with a magnificent seventh-minute goal, shooting from just inside the 20-metre line after typically fluent approach work from Martin Farragher and Ian Burke.
Farragher had been sent off against Moorefield the last day, but with the red card rescinded he celebrated his liberation in style, scoring six points.
Burke was the last starting forward to score, but his influence in holding up possession and laying it off at the right time, every time, was a key component of their attacking strategy.
It was the second goal on 21 minutes that will forever be the masthead for this final. Had something like it been constructed in Twickenham, Joe Schmidt's tactical star would have risen even higher, such were the complex layers of movement and switches of direction.
In real time it was difficult to follow the sequence, so swift were the transfers, but Daithí and Ian Burke had multiple involvements, Michael Lundy and Martin Farragher also played parts before Daithí Burke set up Michael Farragher with the last pass for a deft finish.
It gave them a 2-6 to 0-1 lead and told Nemo what they already knew anyway.
"We knew we'd be let to play football, which was important," said Corofin manager Kevin O'Brien, espousing the values of the club over the last two decades.
"What we believe in won't change and how we play the game and how we conduct ourselves is the thing that will always shine through."
By the break, Corofin's lead was 2-9 to 0-5 and they were able to control the game comfortably and build more great moves that involved so much switching of the play that Nemo just couldn't track.
Nemo made a triple substitution - among those withdrawn was their semi-final hero Tomás Ó Sé - on 38 minutes, but while two of those who came in scored, it had little real impact.
"They were well schooled, they knew what they were doing," admitted Nemo manager Larry Kavanagh.
"We saw by the programme that they had Michael Farragher inside and he came out and caused us an amount of trouble. It's difficult out in Croke Park, we were trying to get Kevin Fulignati to switch on to him but it took us six or seven minutes to do that. They were very slick. Even their kick-passing, they were popping balls left and right and our fellas were looking at it."
One second-half point was better than the next. Martin Farragher's fifth and the second from Daithí Burke - who picked up a sixth medal in 12 months; league, Leinster and All-Ireland hurling medals with Galway; Connacht, Galway and All-Ireland club football medals with Corofin - the most memorable.
The win pushes Corofin to joint-third on the club roll of honour with St Finbar's and St Vincent's, still behind Nemo (seven) and Crossmaglen (six).
"It was beyond my wildest dreams that we could do that," admitted 34-year old veteran Kieran Fitzgerald.
"We were hoping, we felt throughout the year we hadn't put in a 60-minute performance and to do that on the biggest stage of all was so pleasing for us."
Scorers - Corofin: G Sice 1-4 (2f), Martin Farragher 0-6, Michael Farragher 1-1, I Burke, D Burke, D Wall 0-2 each, M Lundy, J Leonard 0-1 each
Nemo Rangers: L Connolly 0-6 (4f), P Gumley, C O'Shea, J Donovan, P Kerrigan 0-1 each.
Corofin - B Power; C Silke, L Silke, K Fitzgerald; C McGrath, D Wall, K Molloy; D Burke, R Steede; M Lundy, G Sice, J Leonard; I Burke, Martin Farragher, Michael Farragher. Subs: C Cunningham for Molloy (48), C Brady for Lundy (48), B O'Donovan for Leonard (55), D McHugh for C Silke (55), C Brady for D Burke (59), D Canney for Martin Farragher (61).
Nemo Rangers - M A Martin; K O'Donovan, A O'Reilly, A Cronin; T O Se, S Cronin, K Fulignati; A O'Donovan, J Horgan; B O'Driscoll, P Kerrigan, C O'Brien; P Gumley, L Connolly, C Dalton. Subs: J Donovan for O Se (38), M Dorgan for Horgan (38), C Horgan for Gumley (38), C Kiely for Dalton (48), C O'Shea for Fulignati (52).
Ref - D Gough (Meath).