The British wrestler, formerly Rayne Leverkusen and niece of late Iron Maiden drummer Clive Burr, beat Nikkita Lyons at the WWE Performance Center in Orlando on 28 April.
Rain, who arrived from PROGRESS Wrestling as its women's champion, secured the victory with a step-up knee shot called Thunderstruck after avoiding Lyons' mid-rope splash.
The episode also featured several first-time NXT appearances, including EVIL confronting champion Tony D'Angelo before Will Kroos attacked him, alongside debuts for Kam Hendrix, Tristan Angels and Tate Wilder.
Can the legacy of an Iron Maiden legend forge NXT's next breakout women's champion?
With international stars like EVIL and Will Kroos appearing, is NXT transforming into WWE's new global wrestling territory?
Is NXT's massive roster overhaul a creative refresh or a sign of a larger strategic shift for WWE's developmental system?