Such is England's intense focus on the game in front of them, they did not even know they had broken yet more records in their World Cup opener.

The Red Roses refuse to spend much time reflecting on their position as favourites, but they cemented that tag with an 84-19 win against Fiji in their opening game to extend their record winning run to 26 Tests.

Hosts New Zealand raised English hopes even more with a shaky start against Australia in the game that followed at a sold out Eden Park.

The Black Ferns are supposed to be England's main rivals for the title alongside France, who beat South Africa 40-5 in the tournament's opening game.

The hosts eventually stormed to a 41-17 win with threateningly impressive individual performances from wings Portia Woodman and Ruby Tui.

New Zealand's second-half resurgence was nothing compared to England's. Such dominance from one team so early on may be bad news for the World Cup as a whole, but Middleton suggested their were signs of cracks in England's clinical facade.

The head coach says nerves were responsible for a slow first half which saw England held to 24-14 by World Cup debutants Fiji.

"That first half showed there's going to be no gimmes in this competition," he said.

"There's been a massive amount of build-up. It's a massive game - the biggest stage there is in one of the iconic stadiums."

A nervous start is understandable given the Red Roses' dominance had been one of the main talking points coming into the tournament.

England have been top of the world rankings since November 2020 and last lost a match in July 2019.

Ever-professional captain Sarah Hunter has consistently refused to discuss anything but the next game in front of her.

She went one further after England's win, claiming the World Cup is "New Zealand's to lose" given they are the current holders.

Hunter's wariness can be forgiven. The Black Ferns have beaten England in four World Cup finals - two of which featured the current Red Roses captain.

New Zealand were hit hard by the pandemic and a lack of game-time meant they suffered two record defeats by England in 2021.

World Cup-winning men's coaches Wayne Smith and Graham Henry were brought in to turn things around, but their impact was not immediately felt as New Zealand were 17-0 down after 30 minutes against their Trans-Tasman neighbours.

A vociferous record crowd of 34,235 - surpassing the previous mark of 20,000 set at the 2014 World Cup - lifted their side.

Woodman completed a hat-trick in the second half and Tui raised the volume further with some blistering runs.

It was only the opening day of the tournament and, of course, it is still all to play for. There are areas where England can improve.

The Red Roses have a much tougher test against France in their next pool game on Sunday and Middleton suspects opposition coaches will learn from Fiji's first half.

The debutants' high-tempo game came as a shock to England and it took them 40 minutes to really get their head around it.

"Fiji were brilliant in that first half and we played into their strengths a bit," Middleton said.

"I don't think all teams will play like Fiji did but they'll certainly have a look at it now."

Another area of concern is England's goal-kicking. Emily Scarratt missed five of 10 conversions with Zoe Harrison taking over and making two of four.

Leaving 14 points on the field is something England can ill afford against France or New Zealand but Middleton says he is "not worried in the slightest".

"I remember having exactly this conversation at the start of [the] 2017 [World Cup]," he explained.

"There was a massive emphasis on Scaz's [Scarratt's] goal-kicking and she went and kicked 10 out of 10 in the next game."

But only minor faults can be found in a record-breaking win. Overall it was a day to celebrate England's collective dominance and individual brilliance.

Flanker Sadia Kabeya continues to push for a starting shirt against team talisman Marlie Packer.

Abby Dow made a try-scoring return six months after breaking her leg and Claudia MacDonald - who thought a neck injury had ended her career in 2021 - claimed four of England's 14 tries.

The Red Roses may be keeping a laser focus on the next game, but their position as favourites becomes more pronounced with every record they break.