Adelaide had too many winners all over the ground for the lacklustre Saints, with a six-goal burst in the last 10 minutes of the third term ensuring its 22.11 (143) to 13.8 (86) win.
Crows captain Mark Ricciuto and Brett Burton were the standouts for Adelaide – gathering 33 and 30 possessions respectively - with Burton also pulling in 12 marks and booting three goals.
Johncock – used both in defence and attack this season – was the surprise-packet of the day with his six goals all coming before three-quarter time.
Robert Harvey worked tirelessly all day for the Saints to finish with 26 disposals and a goal to his name.
St Kilda captain Aaron Hamill won the toss and elected to give Adelaide first use of a stiff breeze favouring the southern end of the ground.
He may have been having second thoughts about his decision as the first term progressed as the Crows used the breeze well to establish a 20-point lead at the first break.
Johncock and Andrew McLeod were prominent up forward for Adelaide – kicking three and two first-quarter goals respectively – while James Begley was solid in defence – racking up nine disposals for the term and setting up play well across the half-back line.
McLeod’s first goal was one for the highlight’s reel – the champion Crow using the breeze to float through a right-foot snap from a seemingly impossible angle deep in the pocket.
The Saints were unable to use the three to four goal wind to their advantage in the second term with the Crows increasing their lead to 27 points at the half.
Johncock continued his day out - adding his fourth - while Scott Welsh booted his second goal after the siren when he was awarded a down-the-ground free kick because Stephen Milne floored McLeod after he had disposed of the football.
Milne’s indiscretion was to be a double-blow for the Saints as the elusive forward was reported by umpire Colin Rowston soon after the incident.
Adelaide blew the game wide open in the third quarter after a brief challenge from St Kilda. Maguire’s third goal for the day kept the Saints within striking distance midway through the term but sparked a six-goal avalanche by the Crows.
Chris Ladhams started the flurry with two goals in as many minutes at the twenty-minute mark and Mark Ricciuto followed soon after to blow the margin out to 45 points.
Brett Burton continued to punish the Saints with three third-quarter goals – with two coming in time-on – and Johncock finished the demolition with his sixth goal after the siren giving Adelaide a 64-point lead at the last break.
With the result beyond question, the Saints outscored the Crows in a lacklustre final term to bring the final margin back to 57 points at the final siren.
Goals to Ian Perrie and Welsh were answered with majors from Nick Dal Santo, Leigh Montagna and Harvey to give Saints fans some sort of consolation after a mainly forgettable performance from their side.
ADELAIDE: 7.3, 11.6, 20.8, 22.11, (143)
ST KILDA: 4.1, 7.3, 10.4, 13.8 (86)
Goals: Adelaide: Johncock 6, Burton 3, Ladhams 3, Welsh 3, Perrie 3, McLeod 2, Ricciuto, Edwards.
St Kilda: Maguire 3, Milne 2, Hamill, Dal Santo, Powell, Wulf, Riewoldt, Ball, Montagna, Harvey.
Best: Adelaide: Burton, Johncock, Ricciuto, Hart, Clarke, Begley, Ladhams.
St Kilda: Harvey, Powell, Maguire, Jones, Dal Santo.
Injuries: Adelaide: Mattner (shin)
St Kilda: Clarke (ankle).
Reports: St Kilda: Milne reported by field umpire Rowston for striking McLeod in the second quarter.
Umpires: Coates, Rowston, Ryan.
Crowd: 44,667 at AAMI Stadium
