Tuesday saw Breakfast reclaim its dominant position, with 36,000 viewers compared to The AM Show's 29,000, while Wednesday saw both networks lose viewers.
In a statement, TVNZ news boss John Gillespie said he was "really happy" with the show's performance thus far.
"Hayley is presenting well with the team, and Jack and her have a great rapport together, we've received a great audience response to the new show."
Read more:
• Review: Why Hayley Holt can't save Breakfast
• Hayley Holt's co-host packs 'a little bit of a sad'
Traditionally, January ratings are always softer than the rest of the year, particularly before the start of the school term.
Last year, Breakfast enjoyed three weeks without any direct competition from Three, as The AM Show didn't launch until February 13.
This year, Mediaworks bosses made a strategic decision to bring both The AM Show and The Project back from summer break earlier, while TVNZ's Breakfast and Seven Sharp remained off-air.
A Mediaworks' spokesperson said: "We're focused on our audience and what they want. We know that many Kiwis are back to their usual viewing habits from mid-January, so we made the decision to be back when they were and it's paid off."
This week's ratings show 39% growth compared to The AM Show's first week back last year, in mid-February.
Breakfast returned this week with new host Hayley Holt joining Jack Tame as Hilary Barry prepares to move to prime time, where she will host Seven Sharp.
Her co-host has yet to be announced, although speculation is mounting that Radio Hauraki host Jeremy Wells is the frontrunner.
TVNZ has confirmed the series will return in just over a week's time on Monday, February 5.
Last year, Seven Sharp hosts Toni Street and Mike Hosking surprised viewers when they announced they would be stepping down from their roles after four years hosting the programme together.
