England's lock Dave Attwood (L) wins the line-out from Australia's Luke Jones during the Autumn International match at Twickenham Stadium, southwest of London on November 29, 2014England's lock Dave Attwood (L) wins the line-out from Australia's Luke Jones during the Autumn International match at Twickenham Stadium, southwest of London on November 29, 2014 (AFP Photo/Ben Stansall)
Victory came just in time for an England side who in the course of the November series had been beaten by both world champions New Zealand and South Africa, albeit by a margin of just three points in both matches.
It was also a boost given it is just under a year until England face Australia at Twickenham in the pool stages of the World Cup.
"Absolutely," said Lancaster when asked if his side were on track for the World Cup.
"It's always difficult going into an autumn (November) series playing the world champions with limited preparation time. We felt we competed well.
"We felt in the South Africa game that we generated the opportunities for them rather than the other way round. We haven't got everything right by any stretch of the imagination. There's still a lot of work to do.
"We'll not look too far ahead because the next game is against Wales (England's Six Nations opener in Cardiff on February 6) but it's always nicer to finish a series with a win."
With last week's defeat of second-tier Samoa taken as read before kick-off, this victory was one England needed to ensure their November campaign was not a write-off.
Saturday's success was just England's third victory in 14 matches against one of the 'big three' -- South Africa, New Zealand and Australia.
- 'Rock solid' -
It came on the back of a commanding scrum performance, an area where England have long enjoyed dominance over Australia, with No 8 Ben Morgan forcing his way over off the back of the set-piece for the home side's two tries.
Fly-half George Ford, given a chance to start against top opposition after impressing against Samoa, kicked England's remaining 16 points in an assured all-round display.
"We were under pressure externally but internally we were rock solid," said Lancaster.
"We always believed in the plan, believed in the players."
Lancaster played down the significance of a win where Australia tries by fly-half Bernard Foley and replacement forward Will Skelton could not prevent a third straight defeat for the Wallabies.
"The tournament (World Cup) will look after itself when it comes around. Australia will have a lot of time together with their new coach (Michael Cheika).
Meanwhile Lancaster was looking forward to having a fully-fit squad at his disposal.
"We've got seven British Lions to come back into the team and the likes of (lock) Joe Launchbury, who didn't make the Lions but is an important player," he added.
And Lancaster insisted there was more to England's game than forward power.
"We're not just a set-piece side, because we're bound to run up against scrums that'll match us," he said.
"Probably the most pleasing thing overall is if you look back at 2014, irrespective of today's result, we scored 26 tries and 21 were by the backs," he added, clearly annoyed by a suggestion that England lacked midfield creativity.
Lancaster praised Morgan, who started the November series as back-up to Billy Vunipola at No 8.
"He has been one of the stand-outs over the last two games," Lancaster added. "He'll be a hard person to shift now."
And Lancaster was equally enthusiastic about the way Ford had taken his chance after fly-half Owen Farrell, who played at inside centre against Samoa but was dropped to the bench for the Wallabies match.
"He was excellent," Lancaster said of Ford. "I thought the accuracy of his kicking game was absolutely spot-on."
However, asked if there was one thing alone he could add to improve England, Lancaster cited currently injured powerhouse centre Manu Tuilagi.
"Manu. If you're going to win all the big games all the time you're going to need all your best players, and he's certainly in that category."