Did Ewen McKenzie offer a smidgen of a smile at the end of the Wales Test? Surely not; as the Wallabies coach loves impersonating a Moai (Easter Island statue) in victory and defeat - and anything in between. But there was a glimpse of a slight grin on McKenzie's granite features when he passed a far more joyous Quade Cooper on the sideline at full-time. And, yes, McKenzie is excused this brief moment of frivolity.

After all, the Wallabies held up best when encountering the best of the Six Nations sides - holding off a vigorous Wales team, especially when down to 14 men in the final minutes, enabling them to end their European tour with gusto. The performance - and the 30-26 result - also ensures McKenzie can relax during his summer break because he won't have to keep justifying himself. All he has to say to ward off the detractors is: "Hey, we've won four Tests in a row. When was the last time that happened with the Wallabies? Only five years ago."

McKenzie's opening months as Wallabies coach have been rugged. But no-one can say he has ever taken the easy option. In many areas, he took the excruciatingly tough decisions - in particular his attempt to improve the team culture; and while there are still some dropped lips among squad members who remain miffed over how the Dublin drink-a-thon was handled officially, everyone now knows McKenzie doesn't play favourites. He won't be conned by anyone - young or old.

And that can only work in the Wallabies' favour. The benefits were there to see at Millennium Stadium.

After a long slump, the Wallabies backline is again starting to appear threatening. Israel Folau has fine-tuned what was often a spluttering engine, and Cooper is showing yet again that anything is possible when his confidence is up.

Quade Cooper produced a dynamic performance for the Wallabies against Wales in Cardiff © Getty Images

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How we rate the Wallabies

• Result: Wales coach Warren Gatland was moaning about several refereeing decisions, but the right team won. The Wallabies were the more adventurous, the more proactive. A rousing tour-ender.
• Scrum: Hallelujah, there almost weren't any scrums in the Test - and the few that were set went virtually as planned. Another gradual improvement for the Wallabies.
• Defence: After strangling Ireland and Scotland, they let two in against Wales; but overall they held up well in Cardiff.
• Combinations: Quade Cooper and Israel Folau again weaved their magic, and Christian Leali'ifano looked better at No.12. The smarter attacking game offered by the Wallabies also had something to do with the input of winger Nick Cummins.
• Attacking mojo: Cooper, Folau … say no more. Maybe even the All Blacks are getting a bit edgy.
• Overall mark: 8 ½ out of 10.
• Greg Growden's original KPIs
• England Test: Scrum unable to provide platform
• Italy Test: Turin win a step forwards
• Ireland Test: Wallabies still not entitled to party
• Scotland Test: Wallabies effective, just what they needed

Cooper is certainly relishing the extra responsibility McKenzie has given him. I, for one, thought McKenzie's appointment of Cooper as vice-captain was strange; but it has worked on this tour. The often-troubled Reds No 10 is a transformed player, and he often led the team.

McKenzie's faith is a crucial factor in Cooper performing with such poise; but so too is the fact that the two other "Amigos" - James O'Connor and Kurtley Beale - weren't on the tour. Strife and distractions seem inevitable whenever two or three of them are together; they are masters of leading the others into a bog. That could be the trick. Maybe from now on, the Australian Rugby Union should make it an edict that the Wallabies operate under a "one Amigo" policy. Never more than one should be in the team at the one time - even when Cooper is confronting his bogey side, the All Blacks.

Unlike several other recent-end-of-season tours, the Wallabies follower, with an improving 6-6 win-loss record to ponder, is not exactly looking upon the following year with dread. Instead all are waiting to see whether Cooper and Folau can continue being such a devastating combination.

As tantalising next season will be observing how Scott Fardy combines with Scott Higginbotham in the Wallabies pack. Australia have been waiting a long time for a mongrel pairing in their back-row, and this could be it: Fardy remaining at blindside flanker, Higginbotham at No.8. While Folau has been the signing of the season, Fardy has been the find - producing much required menace and backbone to an often-flimsy Wallabies pack. Fardy's elevation has been fast, but so exhilarating.

Nonetheless, a heavy shadow still hangs over this European tour. The Wallabies effort against England in the tour opener was abominable - and they can ponder what might have been if they had just used their brains at Twickenham. A Grand Slam triumph for one thing.