Former England and British & Irish Lions coach Clive Woodward believes the northern hemisphere nations are capable of dominating future Rugby World Cups.
The past weekend's Autumn Nations Series saw all four Rugby Championship teams - South Africa, Australia, New Zealand Argentina - lose to their northern counterparts.
The Boks were pipped 27-26 by England at Twickenham, a 14-man Wallabies went down 29-28 to Wales in Cardiff, France beat the All Blacks by a record 40-25 margin in Paris and Ireland thumped Argentina 53-7 in Dublin.
Saturday was the first time the southern hemisphere's three giants (SA, NZ and Australia) had lost to Six Nations oppositions on the same weekend since November 2002 and Woodward believes it was "a wonderful boost for our game".
"Rugby World Cup 2023 is going to be incredible but first we have got two Six Nations to savour. I want to first look at the resurgence going on in the northern hemisphere" Woodward wrote in his
"It is a long overdue development and vital because the Six Nations is the foundation of our international game," he added.
"The south have been bossing the Test arena and World Cups for too long, to the extent that they provided all four World Cup semi-finalists in 2015."
Woodward, who won the 2003 World Cup as England coach, added that he felt it was realistic for Six Nations teams to also dominate future World Cups.
"The Six Nations must be as strong, vibrant and competitive as possible. Not just a fantastic day out, the rugby must be as good as any on the planet and that should certainly be the case in a few weeks.
"I dream of a day when the Six Nations provides three or who knows maybe all four semi-finalists at a World Cup. Why not? It can happen."
When analysing England's win over the Boks, Woodward said he was particularly impressed by young England flyhalf Marcus Smith.
The 22-year-old was flawless off the tee in a 12-point haul, and he also held his nerve amid all the tension of having a kick to win the game in front of a capacity 82 000 crowd.
"Marcus Smith is the real deal, a major talent and goal kicker of the first rank with nerves of steel," Woodward said.