England have discovered for sure what they insist they suspected all along - that New Zealand are more than a compliant warm-up act for this summer's Ashes.
While Australia continue to struggle in their Test series in India, England have encountered plenty more resistance in New Zealand than many experts thought likely.
After day two of the final Test - a potential decider, with the series score locked at 0-0 - England were off the pace on 50 for two in reply to 443 all out at Eden Park.
Steven Finn equalled his career-best six for 125 to ensure the tourists made much better progress than yesterday, taking nine wickets for 193 to follow their one for 250 24 hours earlier.
But they then lost Alastair Cook cheaply, and also Jonathan Trott, in 25 overs of batting before stumps.
It all means that, however they fare over the final three days, there is no doubt England have come up against worthy opponents on this tour - and can expect more of the same in the return Tests back home in May, before the first of their back-to-back Ashes series.
Finn acknowledged that, but pointed out too that England were never under any illusion that the Kiwis would test their mettle.
New Zealand's lowly world ranking, compared to England's second place in the International Cricket Council Test table after their historic victory in India before Christmas, persuaded many that they would coast to success.
Rain, as well as the skills of Brendon McCullum's hosts, prevented that happening in drawn Tests in Dunedin and Wellington.
Here, Peter Fulton's 136 - his first Test hundred - and Kane Williamson (91) shut England out for 68 overs on a very good batting surface.
Asked whether New Zealand might end up being every bit as hard to beat as Australia this year, Finn said: "Yes, certainly.
"By no stretch of the imagination did we come over here believing that this was going to be an easy series.
"We know that the wickets are good over here, and we'd have to work hard to win games of cricket.
"Through the Twenty20 and one-day series, and now the Test series, it's been a pretty even contest all the way through."
England struggled throughout yesterday, and even today, to get the ball to swing as New Zealand piled up a formidable total; then when the hosts set out with the new ball, Trent Boult immediately found lateral movement in the air and was rewarded with Cook and Trott's wickets.
Finn added: "By no stretch of the imagination have we under-estimated New Zealand.
"They've played some excellent cricket - and so they should, because they've got some excellent players.
"We know we've got a fight on our hands ..."
Finn's own contribution, if a little flattering after he cashed in with four wickets for 13 runs to see off the tail, was significant.
"I felt as though I've bowled better in this game than in the previous two," he said.
"My lengths have been better, fuller, making the batsmen come forward more often than I have done in the previous games.
"I was fortunate to get (some of) the wickets today. But as a team, we felt we deserved some fortune."
The tall seamer was indebted too to the athleticism and safe gloves of Matt Prior, who took five catches behind the stumps - including a brilliant take off Finn to at last see off Fulton after his seven-and-a-half-hour stay.
"It's nice to know he can leap like a salmon down the leg-side and catch a couple of those," he said.
"He is up there with the best wicketkeeper-batsmen in the world, if not the best.
"So to have him behind the stumps is fantastic, and he's been exceptional ever since I started playing for England - and before that.
"He is the person who provides the energy in the field, who buzzes through, and it's great to have him to feed off.
"He is integral to us as a team."
Finn also had a plausible theory as to why there was little swing for England, with no square either side of a drop-in pitch to allow the ball to scuff naturally.
"It is strange. There's a bit of a ridge all around the wicket.
"As the batsman hits the ball into there, it sort of plugs rather than runs off," he said.
"In terms of getting the ball to reverse-swing - which we've been very good at (elsewhere) - and getting the ball to do anything, it's been very difficult because of the lush nature of the outfield.
"The ball has stayed smooth, which has meant it hasn't done much ... but we have to deal with that.
New Zealand stayed one step ahead thanks to new-ball rather than reverse-swing - and although their batting faltered slightly today, Williamson said: "We are happy with our first-innings effort, and it was good to pick up a couple of wickets at the end of the day - key wickets at that."