The decision to move Head up the order will go down as one of the great Ashes tactical moves.
Faced with having to replace Khawaja, just as they did in the first innings, Australia realised the best plan on the difficult Perth pitch was attack. Left-hander Head, who has opened in the past, was moved from number five with licence to play his natural game.
The outcome was sensational and, even at this early stage, could define the series. Head climbed into the England bowling, bringing debutant Jake Weatherald along for the ride.
Head backed off and scythed the ball through the off side. One of his four sixes, a slash over third man off Carse, was outrageous. England lost their line, somehow failing to locate the stumps or Head’s body.
Weatherald, who overturned being given caught behind off Jofra Archer on seven, miscued Carse to end an opening stand of 75, but it did not halt Australia’s momentum.
Marnus Labuschagne eased into the slipstream of Head, who by now was unstoppable. He clattered Archer baseball-style back over his head for another maximum.
The only quicker Ashes century, 57 balls, was made by Adam Gilchrist in this city – across the Swan River at the Waca 19 years ago. Given the context, this innings might well have surpassed it in terms of quality and the Perth Stadium rightly rose to acclaim Australia’s magnificent match-winner.
By the time Head skied Carse into the leg side, only 13 runs were needed. He left to a spine-tingling ovation, a lasting image from one of the most incredible Ashes Tests.