Archie Thompson became Australia's second-highest goal-scorer of all time and netted one of the fastest hat-tricks from a substitute in international football as the Qantas Socceroos hammered Guam 9-0 in Hong Kong.

Holger Osieck's team were already coasting at 4-0 up when Thompson replaced Eli Babalj, and the introduction of the pacy marksman put hapless Guam's demise beyond doubt.

Thompson plundered three goals in the space of eight minutes on Friday, set up another for Mark Milligan with consummate ease and is now just one goal away from equalling Damian Mori's all-time record of 29 Socceroos strikes.

The hefty win could prove crucial to Australia's hopes of qualifying for the East Asian Cup.

Progression from the preliminary tournament is expected to go down to goal difference, and Australia's direct rivals North Korea could only manage a relatively pedestrian 5-0 win in their match against Guam, with both of the group's top-two teams now boasting a goal difference of plus 10.

While it will be difficult for Guam's unfortunate coach Gary White to remember, there was a time in the match before the flood gates opened.

Central Coast Mariners star Tom Rogic enjoyed the first sight of goal in the fourth minute, drawing a smart save from Guam goalkeeper Doug Herrick.

The deadlock did not last much longer and the Socceroos were ahead eight minutes later, Aaron Mooy scoring straight from a free-kick with the ball deflecting home off the underside of the crossbar.

In the 19th minute, Babalj combined with former Melbourne Heart team-mate Michael Marrone, who advanced down the right flank and crossed for the Red Star Belgrade striker to slot home from close range.

Guam weathered a period of sustained pressure midway through the first half, with the frustration of Australia's coaching staff evident as a succession of chances went begging.

Improbably, it looked as if Guam would survive until the half-time break just two goals down, but with four minutes left in the half, Marrone cut in from the right flank and coasted into the penalty area, dispatching a clinical finish beyond Herrick to make it 3-0.

Australia continued their assault on the Guam goal early in the second half, with Mooy guilty of a glaring miss from point-blank range five minutes after the restart.

On 55 minutes Babalj did make it 4-0, tucking home after Matt McKay beat the offside trap and slipped the ball neatly beyond Herrick for his colleague to finish.

Babalj was replaced by Thompson moments later, and the Melbourne Victory man made a spectacular impact.

In the 58th minute the veteran forward received a pass from McKay with his back to goal, turned sharply and blasted a strike past the despairing keeper.

Less than three minutes later Thompson smacked home his second at the near post, and when Scott Jamieson was brought down for a penalty in the 63rd minute, there was no other candidate to take the spot kick.

Thompson dispatched the penalty with aplomb, putting Australia 7-0 ahead.

He had a good header gratefully saved by Herrick in the 68th minute, before turning his hand to providing the goals.

Bursting beyond Guam's static backline, Thompson checked, spun around and floated the ball to the back post, where Milligan arrived to casually nod home.

The impressive McKay was withdrawn with less than 10 minutes to go, and his replacement Richard Garcia had no intention of missing out on the glut of goals.

The Melbourne Heart midfielder had been on the pitch for barely 60 seconds when he glided beyond two defenders and prodded home for the Socceroos' ninth.

Mooy and Aziz Behich both went close to inflicting further misery on Guam in the closing exchanges.

Australia's final game is a winnable match against Chinese Taipei on Sunday, while North Korea's last outing is a more difficult assignment against hosts Hong Kong.