The reigning world champions ran out 5-0 winners in Los Angeles - Moore's own goals plus strikes from Ashley Hatch and Mallory Pugh sealing the victory.
Moore's nightmare began in the fifth minute when, in her attempts to clear a cross from the left, she deflected the ball beyond New Zealand goalkeeper Erin Nayler.
Just a minute later the Americans were 2-0 up as a cross by Sofia Huerta on the right skimmed off Margaret 'Midge' Purce's head and onto Moore.
The 25-year-old had no time to readjust and could only look on as the ball glanced off her head and into the net.
Moore's unwanted hat-trick was completed in the 36th minute as she failed to get her feet sorted in time before skewing a low cross from the right into the net off her left foot.
New Zealand manager Jitka Klimkova opted to substitute Moore four minutes later on what was her 50th senior cap for her country.
Veteran USA defender Ali Kreiger tweeted her support for Moore during the match.
"I'm so proud of the USWNT - 3-0 at half-time vs NZ - but I do have to say my heart goes out to Moore," wrote Krieger.
"This beautiful game can be cruel sometimes and today doesn't define her! I can't imagine the pressure she feels at the moment and I hope she's okay."
Meanwhile, head coach of American team NJ/NY Gotham added: "Meikayla Moore will bounce back.
"She's playing against the best team on the planet, who are delivering unreal balls into the box. For all the keyboard warriors giving her a bit of s***, get back in your mum's basement.
"She's doing things that 99.9 per cent could only dream about! Good player!"