Former England captain Lawrence Dallaglio believes his country will complete the most impressive Rugby World Cup win of all time if they are able to overcome South Africa in Saturday's final.

Dallaglio was one of the heroes of England's triumphant 2003 World Cup campaign and also starred as a grizzled band of forwards dragged a less-accomplished side to the final four years later, where South Africa were the victors in Paris.

But the manner in which Eddie Jones' men have dispatched opponents of New Zealand and Australia's calibre in the semi and quarter-finals leads Dallaglio to believe the class of 2019 will stand apart if they are able to complete a clean sweep of rugby's southern hemisphere giants.

"If they win the World Cup, which they've got every chance of doing, it will probably be the best World Cup win ever," he told Sky Sports.

"While they might have had it easy in the pool stages, they will have had to beat Australia, New Zealand and South Africa [to lift the trophy].

"If you can do the Tri Nations and lift the trophy at the end of it, then you deserve to be crowned world champions."

England produced what is likely to be viewed as a generation-defining performance in their semi-final, dominating from the first whistle to win 19-7 and hand the All Blacks their first World Cup defeat for 12 years.

By contrast, South Africa and Wales engaged in a battle of attrition on Sunday in Yokohama.

"The first game was amazing in the sense that you were absolutely captivated by what happened," Dallaglio said.

"The second game was a real kick-fest – 81 kicks [front hand]. It wasn't easy on the eye.

"That's the way it went, it was a bit of an arm-wrestle. South Africa came out on top as we probably thought they would if the game panned out that way."

He added: "England have got to play a really tough opponent. Naturally there's a bit of excitement, everyone's now expecting England to go in there and do what they did against the All Blacks.

"You can't expect that because it doesn't happen like that in rugby. I guess what South Africa have shown in this tournament is they're going to be a really difficult nut to crack. They've only conceded four tries – two of them in the first game against the All Blacks."