WALES boss Warren Gatland hailed his players' composure and fitness after they moved towards the World Cup quarter-finals with a memorable victory over Australia.

The Pool D showdown did not disappoint as Wales cruised into a 26-8 lead before Australia went within a point of drawing level - and were then finally broken by replacement Rhys Patchell's late penalty.

Wales' 29-25 triumph keeps them on course for a potential last-eight clash against France or Argentina - but Australia appear to be hurtling towards a quarter-final appointment with England and their former head coach Eddie Jones.

It was Wales' second win in succession against Australia but a first World Cup victory over the Wallabies since 1987.

"I would like to see them (Wales players) celebrate tonight," Gatland said. "They deserve to celebrate - it was a tough game and a great win.

"Australia were really good in the second half, put us under a lot of pressure and had a lot of ball.

"And it became a typical Wales-Australia clash, going right down to the wire. To win that is very pleasing, and that means the pool is our own destiny.

"Our game-management has improved significantly. It was good in the autumn last year, and particularly in the Six Nations. We've learnt a lot from those experiences.

"Even though we were under a lot of pressure in that second half, I thought our composure and fitness were really good and we soaked up a lot of pressure.

Gatland confirmed fly-half Dan Biggar failed a head injury assessment - he was replaced by Patchell during the first half - and that full-back Liam Williams rolled his ankle.

"Dan failed an HIA," Gatland added. "I had a chat with him afterwards.

"He's disappointed he had to come off, but it is important we go through the (HIA) protocols.

"Rhys (Patchell) did a fantastic job for us. He's been criticised a lot for his defence in the past. We changed a few things about the way he defended, and I thought his line speed was excellent.

"He made some big tackles for us and controlled the game pretty well. It was a big match for him to come on early and get the win, and he will get a lot of confidence from that.

"It was one of the toughest Test matches they've played in a long, long time. We need to make sure we recover. It's nice getting a decent break before getting our next game against Fiji."

Wales looked home and dry when they led through tries by centre Hadleigh Parkes and scrum-half Gareth Davies, with Biggar and Patchell kicking 19 points between them, including Patchell's 72nd-minute clincher.

Wing Adam Ashley-Cooper, full-back Dane Haylett-Petty and captain Michael Hooper claimed touchdowns for Australia, with Bernard Foley kicking a penalty and Matt Toomua booting seven points.

But Wales held out to claim victory and give their World Cup campaign considerable momentum.

"It was just about winning, really. It wasn't about knockout stages," Gatland said.

"We won some key turnovers towards the end of the game. It was pleasing to handle the six-day turnaround from the Georgia game, which wasn't an easy encounter.

"I want the guys to look after themselves tonight, but they deserve to pat each other on the back. It's a big confidence boost for the next couple of games.

"It's important we prepare the best we can and don't take anything for granted. We've got to be as clinical as you possibly can."