Sam Burgess’ leap of faith to switch codes has been validated with a Rugby World Cup debut and praise from one of England’s greatest-ever players following their tournament-opening victory over Fiji.

The former NRL star earned a standing ovation from the capacity 80,000-strong Twickenham crowd when he jogged on with 20 minutes still to play in the 35-11 win.

He surely made coach Stuart Lancaster sit up and take notice with several powerful runs, coupled with some key offloads, to spark the England attack.

He came on with England up 18-8, then two of his side’s four tries came after Burgess’ injection as they secured a precious bonus point in a tricky pool.

But the Clive Churchill medallist in South Sydney’s grand final win last year had a forgettable first involvement, falling for a subtle dummy from giant Fijian winger Nemani Nadolo which led to an embarrassing missed tackle and clean line-break.

He recovered to have a key impact as England piled on late points, twice combining well with fullback Mike Brown, comfortably the best player on the park with two tries.

Brown made a splitting run late in the match, where Burgess received the ball after backing up in support – before the code-hopping star returned the favour with a neat offload which nearly put Brown over for his hat-trick try.

It was enough to impress England’s World Cup champion Jonny Wilkinson – who was commentating on the match for English television.

“You can’t underestimate the impact Sam Burgess and Billy Vunipola made when they came on,” the 2003 World Cup winner said.

“Burgess made two or three big offloads and brought some energy to that performance.”

Burgess aside, Australia would’ve been heartened for much of the contest by a less-than-convincing display from their Pool A rivals England.

The tournament co-hosts turned the ball over 11 times and their famed scrum was put under constant pressure from the unheralded Fijian forwards.

“They certainly won’t be panicking in the Australian and Welsh camps,” said England’s World Cup-winning coach Sir Clive Woodward.

The Wallabies open their tournament against Fiji in Cardiff on Wednesday (Thursday morning AEST), with the outside backs no doubt keeping an eye on the barnstorming 130kg Nadolo who skittled England’s defenders on several runs and scored his team’s only try.

That will be followed by a clash against Uruguay on Sunday on a short turnaround.

They then round out their group games with the all-important fixtures against England and finally Wales, both of which will be played at Twickenham.