The biggest rugby crowd ever seen at Allianz Stadium (formerly Sydney Football Stadium) of 42,889 turned out on a beautiful afternoon, but both sides failed to take advantage of the conditions in a stop-start and mistake-riddled performance.
Wales appeared set to break their 43-year drought in Australia, with their only ever victory down under coming way back in 1969.
The Six Nations have been competitive in all three Tests, but Australia showed composure to sweep the series as they now set their attention on the four-nation Rugby Championship and Bledisloe Cup starting in August.
After penalty goals were traded in the first half, the match didn't come alive until the final 20 minutes, when Wales took a 16-12 lead with a try to No.8 Ryan Jones.
To their credit, the Wallabies hit back almost immediately, with centre Rob Horne the sole try-scorer for Australia for the second straight week.
Horne somehow held onto the ball to ground it, despite the attention of Jonathan Davies who looked like he'd forced a mistake with a last-ditch tackle.
However the TMO said Horne maintained control of the ball, and the Wallabies went back up by one, 17-16.
Although Wales got back in front again, Horne's try was crucial as the Wallabies remained undefeated against the Red Dragons in their past seven encounters.
Returning Wallabies fullback Kurtley Beale showed the effects of weeks on the sideline with a shoulder injury, after struggling with his execution throughout.
Australia led 12-9 at halftime after Barnes and Halfpenny traded penalty kicks.
The Wallabies were guilty of not taking their chances and were thoroughly outplayed at the scrum and line-out.
Wales suffered a major setback in the first half with Sam Warburton copping an accidental knee to the head from Pat McCabe. He wasn't able to stop vomiting on field as he left the field with concussion.
McCabe broke his nose in a separate incident and also didn't return for the second half.
