Wales star Jamie Roberts says he was 'shaking for 80 minutes' when World Cup heavyweights England and Australia collided at Twickenham and the tournament's pool of death claimed its inevitable high-profile victim.
Australia's 33-13 victory three days ago dumped host nation England from the tournament with indecent haste.
It means that Wales and the Wallabies now meet in a group decider this weekend, with the winners facing a probable last-eight appointment with Scotland or Japan, while the losers can realistically expect to face twice world champions South Africa.
Roberts, who watched the game with friends at Rosslyn Park Rugby Club in London, knows it could easily have been a different outcome and Wales would have found themselves potentially playing an eliminator on Saturday.
"I was shaking for 80 minutes," Roberts said. "It was like playing a game, expending as much energy.
"When it got to 20-13, I am sure Wales were panicking a bit, but Australia came through, so we are delighted to get through to the quarters.
"But it doesn't take the importance off this week. All is still up for grabs - it's a huge game."
By the time Wales begin their quarter-final preparations early next week, England's World Cup squad will have dispersed, their dream of global domination shattered just three games and 16 days into the competition.
"It is a brutal pool, and it was always going to be three teams missing out," Roberts added. "That's what makes the World Cup so exciting - they are such fine margins.
"The question is being asked of England not qualifying. We beat them by three points. We could have lost that game and England could have been going through and the questions asked of us.
"I feel sympathy with the difficulty of the group and how ruthless it has been. It is disappointing as the host nation, and not to see them through is hard for the fans as much as anyone."
Wales will face a Wallabies side shorn of flanker Michael Hooper, who serves a one-match ban after he was cited for foul play during the England match, while full-back Israel Folau is a major injury doubt due to ankle trouble.
Either way, though, Wales must halt a run of 10 successive defeats against Australia, having not toppled the Wallabies since November 2008.
"He (Hooper) is one of their best players, and he's not playing, so it is good for us, but whoever comes into the back-row will be a really good player," Roberts said.
"They are a team that showed on Saturday that when they get things right in attack, then they are one of the best teams. It's one of the biggest challenges in defence that we have faced.
"Folau is a special player, up there with the best players in the world. His abilities as an athlete are frightening and special, if put in space.
"A few of the boys have experience defeating Australia in Australia (with the 2013 British and Irish Lions), and I remember in 2008 playing against them with Wales.
"You look back at the last seven years, and it's the same old story. There is no hiding from that. The last 10 minutes in games against them have killed us on many occasion, and hopefully what's on the line this week will bring out the best in us."
Saturday evening could be a red-letter one for Welsh sport, with a Wales rugby victory securing top spot in Pool A and the Wales soccer team needing a point against Bosnia to secure Euro 2016 qualification.
"It's a wonderful time to be a part of Wales sport," Roberts said.
"A few of (the) lads saw Aaron Ramsey play for Arsenal (against Manchester United) on Sunday and caught up with him afterwards. He's as excited as anyone. It's up to us to keep it going and keep it moving forward.
"The atmosphere there (at Twickenham) at the moment, it's pretty incredible to play in front of that many Wales fans. That's awesome. The game will be an incredible spectacle."
Wales head coach Warren Gatland will name his team on Thursday, with full-back Liam Williams and prop Paul James, who have been absent through concussion and calf muscle trouble, respectively, set to be in the selection mix.
Wales assistant coach Rob Howley said: "We have a clean bill of health, and that is the first time I've been able to say that over the last six weeks."
Source: PA
