And despite the fact that the Australians boast a 100 per cent record in those fixtures, Pienaar is convinced Wales have what it takes to turn the tables in a month's time, even if he does reckon beating the All Blacks will prove a bridge too far just a week earlier.
"Wales showed in June that they are more than capable of beating Australia - they should have won at least one of those games," Pienaar told the Western Telegraph.
"They have made big steps over the past few years but need to win a big game and they have a great chance against Australia because a packed Millennium Stadium is an amazing place to play.
"New Zealand will be tough because they are amazing side playing quality rugby. They are getting better and better it seems.
"It will be hard for anyone to beat them because they have a settled team that has been together a long time with players like Dan Carter and Richie McCaw.
"But Australia are different, they have had a few bad injuries and that meant that they weren't able to have any continuity in the Rugby Championship. They've got some important players back now and they will be looking to them to be their inspiration and fire them up again."
One man set to inspire Wales this month and next is Blues full back Leigh Halfpenny.
The 23-year-old missed out on playing against Pienaar on the 2009 Lions tour but his form in the three seasons that have followed has been particularly impressive.
Halfpenny's heroics with the boot have seen him take over the mantle as his country's number one points machine and fellow place kicker Pienaar knows he could be key to Wales' hopes of a huge November and December.
"In Test rugby you need to kick every point you can and Wales are very lucky to have Leigh Halfpenny," added Pienaar, who was understandably impressed with Halfpenny's remarkable 94 per cent success rate on Wales' summer tour.
"He kicks the ball a long way and has proved that he can slot them over from anywhere in pressure situations and that gives a boost to his teammates and also worries the opposition.
"His kicking is going to be massively important this autumn because there will be some tight games and having the ability to keep the scoreboard ticking is key."