Warren Gatland hailed his Wales players for digging deep after they ended their long losing run against Australia.
Wales' 9-6 victory at the Principality Stadium was their first over Australia since 2008 and came at the 14th attempt.
Substitute Dan Biggar's 77th-minute penalty also gave Wales a seventh win on the bounce against all opponents – their longest unbeaten run under Gatland and best since 2004-05.
Six of Wales' losses in that 13-Test Wallabies sequence had been by five points or less, and head coach Gatland admitted: "I was struggling in the last few minutes.
"I thought it was deja vu – that we were going to lose in the last minute, but the boys dug deep.
"From a defensive point of view it was the most comfortable I have ever felt against Australia."
Full-back Leigh Halfpenny missed two easy first-half penalties that looked to have derailed Welsh victory hopes.
But Halfpenny, the third-highest scorer in Welsh international rugby history behind Neil Jenkins and Stephen Jones with more than 700 points, managed two successful strikes off the tee before Biggar came up trumps.
Halfpenny was off the pitch at that point, having been felled by a high tackle from Samu Kerevi, which meant Biggar assumed kicking duties as he edged Wales home after Bernard Foley and Matt Toomua kicked penalties for Australia.
"I didn't think I would see the day when Leigh would miss two (kicks) in front of the posts," Gatland added.
"He is so focused and I wasn't worried about him missing the kicks, it was more affecting the rest of his game.
"His performance was outstanding. He ran really well – that was a pleasing aspect. If he had missed kicks like that in the past, his game might have gone to pieces, but world-class players don't let that happen.
"He carried on with what was in front of him."
As for the Kerevi challenge, Gatland said: "I thought the tackle on Leigh was reckless.
"It was potentially a yellow card. He was going to make contact with him, but he has left that shoulder in. He could have turned his back or put an arm out to soften the blow.
"The hard thing for Leigh is that he has now got to go through the return to play protocols. We will make sure he is right.
"It is a tough job out there for a referee. If the referee puts his hand up and says he has made a mistake, I am happy enough with that."
The victory was the first time since 1981 that Wales have won a Test match with a single figure-points total – they beat Ireland 9-8 on that occasion – and pressure will now increase on Wallabies head coach Michael Cheika.
It was Australia's eighth defeat from 11 starts this year and Cheika said: "There were too many small errors, whether at the lineout or indiscipline, and they cost us.
"The pressure we built up we released by either infringing or losing the ball at the lineout.
"Wales have a strong defence. They kicked a fair bit and made a couple of good decisions and we didn't execute a couple of key moments and released a pressure valve on the opposition.
"Wales are a good team – they are ranked third in the world for a reason. It was a tight game and this one went against us.
"Those things have happened to us this year and we have got to take that on the chin, understand what we did well and improve the things we didn't do well and get a win next week."