North, South void has been filled
The 34-year-old's side became the first Northern Hemisphere side since England in 2003 to beat all three Southern Hemisphere teams (New Zealand, Australia and South Africa) in a calendar year.
Best was especially proud that his patchwork Irish side, which saw replacement players playing out of position after three key backs were substituted, had somehow eked out a victory.
The Irish had seen a 17-0 advantage evaporate, with the Australians taking the lead after an hour only for Keith Earls to grab a third try for Ireland and Paddy Jackson convert it.
"It's obviously a pretty big achievement to do that and with so many players who have played in those games, is a good sign of our ability and depth.
"Especially after the World Cup last year when it was said there was a big void between north and south [all four semi-finalists were from the southern hemisphere]. We feel we can compete with all the best teams now and since Joe [Schmidt] has come in, it has been about consistency and we feel we have shown that consistency," Best said.
Best, who has done his chances of captaining the British and Irish Lions on the daunting tour of New Zealand next year no harm at all, said he had been especially proud to win his 100th cap with such a bunch of teammates.
He was, though, quite surprised to hear that his father had been overcome with emotion before kick-off.
"I hope you have got my father being emotional on tape because I haven't seen it in 34 years," joked Best, who walked out in front of the 51,000 spectators accompanied by his two young children.
"We talked about a squad ethic and to lose guys early in the week [Jonathan Sexton and Robbie Henshaw] and then Sean [O'Brien] on the morning of the match, you just hope the replacements will step up.
"The changes in personnel you make during the game, you ultimately ask them for a real want and desire and they did that today. The good thing is, it wasn't perfect but it was good enough. For me as a day for 100 caps it is really, really special.
"Even more so because they are a magical bunch of guys to have as teammates."
Schmidt, who had an immediate impact on an out-of-sorts squad when he took over in 2013 winning two successive Six Nations titles in 2014 and 2015, said the victory was special.
"Certainly for me since, I've been associated with the Ireland team, this is one of the proudest days. They have shown immense character, Kieran Marmion, who is a scrumhalf and had to play on the wing, well his tackle on David Pocock was phenomenal.
"Simon Zebo [who came on early for injured fullback Rob Kearney] said it was like a creche out there and he felt like the old guy. It says a lot about how he looks after kids because they were all over the place," Schmidt joked.
Schmidt, who guided Leinster to two European Cup trophies before taking the Ireland post, said it spoke volumes for the squad that Josh van der Flier, the replacement in the starting XV for O'Brien, had been named man of the match.
"I think we got the edge because the boys up front did a great job. When you lose a player like Sean O'Brien so shortly before the match and his replacement is man of the match that is just what you want," Schmidt added.