The Socceroos attack is starting to click under Graham Arnold after they thrashed Nepal 5-0, but the coach still left their World Cup qualifier frustrated on Thursday.

Australia had all the possession and territory, creating countless chances but struggled to finish in Canberra against the team ranked 161 in the world.

Arnold admitted his side should have scored more goals but said he remained confident his attack was headed in the right direction.

"We worked hard on the last camp with our attacking patterns and the two sessions we had here was all about attack," Arnold said.

"It's coming together, we're creating those chances which is great, it's a big improvement and now it's all about the final touch which is the finish.

"It's about creating chances and then being ruthless and finishing them off.

"But it's not easy against 10 players behind the ball and you have to give credit to Nepal who kept working hard all night."

The Socceroos were never challenged and dominated from start to finish against the Group B minnows as Jamie Maclaren scored his first international hat-trick.

Maclaren had scored just one goal in 13 appearances leading into the game but showed his class in front of 18,563 fans in Canberra.

Australia opened the scoring with a set-piece move on six minutes when Aaron Mooy found Craig Goodwin and his low drive couldn't be contained before Maclaren fired in the blocked shot.

The second goal arrived when Aziz Behich crossed for Rhyan Grant who headed back across the face of goal and Maclaren to score from point-blank range on 19 minutes.

Scottish-born Harry Souttar then made it three as the 198cm defender scored on debut after heading in a well-hit Goodwin corner.

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In pics: Australia vs Nepal

All the action as the Socceroos managed to make heavy weather of a 5-0 win...

It should have been 4-0 on the stroke of half-time when Mathew Leckie scored a deflection goal that was incorrectly ruled offside by the linesman.

Goodwin looked certain to score his first international goal in the second half but his back-post header was denied sharply by goalkeeper Kiran Chemjong.

Souttar celebrated a brace when he headed home on 59 minutes but the shot took a deflection and it officially went down as an own goal to Dinesh Rajbanshi.

Maclaren completed his hat-trick in the 90th minute after collecting the ball from Irvine's chest inside the box and finishing sharply.

Nepal coach Johan Kalin said it was a "nightmare" trying to stop the Socceroos' set piece but emphasised he was proud of their second half.

"I think they wanted to score more goals, of course, after that start. So to hold them the way we did in the second half there is no shame in that," Kalin said.

"In the first half we had a nightmare start conceding after five minutes and we had problems on crosses and set pieces with their very tall defender.

"It was a tough team we were playing against, a quality team."

The Socceroos have begun their road to Qatar 2022 with two strong wins and now face Taiwan away on Tuesday before players return to their clubs.