A disputed second-half goal to Eddie Ockenden was enough to maintain the Kookaburras’ stranglehold on the trophy, the last major men’s hockey tournament before the London Olympics.
The Spanish argued the goal came from a dangerous Liam De Young pass and should have been disallowed but Korean umpire Kim Hong-Lae waved aside the protest to give Australia the lead.
In blustery conditions, Australia dominated early stages, denying Spain possession with their trademark quick passing game.
But the Spanish settled into the match mid-way through the first half, with both David Alegre and Roc Oliva splitting the Australian defence but sending their shots wide.
The scores remained 0-0 at half-time, both teams probing for weakness but unwilling to commit men forward with the trophy on the line.
Australia finally broke the deadlock late in the second half, with Ockenden emerging from a goalmouth scramble to latch onto De Young’s high pass.
While Spain threatened in the final minutes, they could not crack the Australian defence.
Earlier, Holland took third position while Pakistan defeated South Korea by 5-4 to take seventh position in the event.