England appeared in control early on day two at 65–1, leading by 99, before collapsing to 164 all out after losing four wickets for 11 runs in a post-lunch slide sparked by Scott Boland.
Set 205 to win, Australia needed just 28.2 overs as Head - promoted to open in place of the injured Usman Khawaja - struck a 69-ball hundred and finished with 123 from 83 deliveries.
Stokes said England tried several plans to halt Head but "he had an answer for absolutely everything," calling the innings "pretty phenomenal".
He rejected suggestions that England's aggressive batting approach was misguided, arguing that players who showed intent were the ones who found success on a bowler-friendly surface.
Despite the heavy defeat, Stokes highlighted England's first-innings bowling, which dismissed Australia for 132, as a key positive.
With a long break before the day-night Test in Brisbane on 4 December, he urged his side to absorb the disappointment but avoid carrying "baggage" into the second match.
"It's crucial we get back to the mindset we had before this game," Stokes said. "We need to win in Brisbane, and we're still confident in our abilities."
Will Jacks is set to make his first Test appearance in almost three years after England named their starting XI for the second Ashes encounter against Australia that starts in Brisbane on Thursday.
Pat Cummins is set to miss the second Ashes Test against England in Brisbane after Australia named a squad of 14 for the encounter that did not include the captain.
England captain Ben Stokes has come out and said he will accept criticism for his team's performance in the first Ashes Test but has pushed back at jibes that the tourists are "arrogant".
Travis Head says he is happy to continue opening the batting for Australia if that is what the team needs from him to win The Ashes against England.
