Looks like the undercard starts around 6AM or so with the main event at 10AM NZ time. Unfortunately, the All Blacks game is then.
https://news.sky.com/story/fury-v-ngannou-start-time-undercard-how-to-watch-it-and-why-the-cross-over-fight-is-happening-12987618
https://news.sky.com/story/fury-v-ngannou-start-time-undercard-how-to-watch-it-and-why-the-cross-over-fight-is-happening-12987618