Spain looked a little out of sync in a first half in which Australia led for much of the way, but they turned it around in the final minutes of the second quarter to take a 37-32 lead into the locker rooms.
But where that first half had been a good contest, the early part of the second half was one sided, Spain outscoring the Australians 26-10 in the third period.
Australia had plenty of reasons to be positive about their first-half performance, while a frustrated Spain coach Sergio Scariolo called time-out after Matt Dellavedova put the Boomers 17-13 up and the gap was at five at the end of the first quarter.
Spain began to turn the match around in the second, with Pau Gasol levelling it at 21-21 from the free-throw line as part of a 9-0 run that flipped the game.
Australia kept fighting and were still in the game at half-time, but it was a different story thereafter.
Back-to-back threes from Rudy Fernandez and Pau Gasol helped power Spain into a 47-32 lead, and another long-ranger from Fernandez pushed the advantage to 59-37 late in the third quarter.
Australia closed the gap late on as Spain turned to their bench players, but the result was beyond doubt.
Pau Gasol led Spain with 20 points while his brother Marc had 12. Fernandez had 17 points, hitting four of five attempts from three-point range.
Joe Ingles and Brad Newley had 12 each for Australia, with Patty Mills adding 11.