The 19-year-old Aucklander added 9cm to her national record when she cleared the bar at 4.80m at the national track and field championships in Dunedin on Saturday.
The attempt was also 3cm clear of the previous Oceania record, set by Australian Alana Boyd in January, and is the best vault by any woman in outdoor competition this year.
Boyd attempted to reclaim the record a few hours later at the Melbourne World Challenge, but could not clear the bar at 4.81m.
‘‘I couldn't ask for a better build-up to the world indoors and Rio with these competitions,'' McCartney said.
‘‘These heights are what I want. It makes medalling [at the Olympics] look realistic.''The gold medal-winning vault at the 2012 London Olympics was 4.75m, while the world record is 5.06m, set by Russian Elena Isinbaeva in 2009.
McCartney, who is quickly becoming a pin-up girl of New Zealand athletics, was ranked 19th in the world before Saturday, but now bolts into fifth place before the world indoor championships in Portland later this month.
McCartney, who had earlier comfortably cleared the 4.70m mark with her first attempt, successfully vaulted 4.80m on the all-important third and final attempt.
‘‘It did take a few attempts to get there, but that last attempt was one of the better jumps I have probably ever done, so I was really happy with it,'' she said.
‘‘That's why I started on an early height, just to get a few jumps in.''
McCartney started at 4.35m, before clearing 4.50m and 4.70m with her first attempts. After just missing out on the record with her second attempt, she brought the crowd to its feet with an excellent third vault.
The bar then went up to 4.85m, which McCartney almost pulled off with her third attempt, the only attempt she went through with the vault.
‘‘It took a couple of attempts to get my head back into it. I had to refocus,'' she said.
‘‘It can be hard. My goal was to go out and do 4.80m. Going up to 4.85m, I had to refocus on it. I was really happy to get a good attempt up on the last one.''
Canterbury's Louise Richards (18) was second behind McCartney with a personal-best 3.15m.
Other highlights on the final two days
● Former Otago representative Marshall Hall, of Southland, won his sixth senior men's discus title with a 56.77m heave.
● Aucklander Matthew Wyatt added the senior men's long jump title to his 100m title he won last Friday. Wyatt, who finished second last year, produced the winning 7.58m jump with his fourth attempt. Jordan Peters, of Manawatu, was second with a 7.49m best.
● 2014 Commonwealth Games hammer throw silver medallist Julia Ratcliffe won the senior women's hammer throw with a 65.93m throw, the longest winning throw in the history of the event at the national championships.
● Canterbury's Fiona Morrison set a resident record [13.21sec] in the senior women's 100m hurdles. She pipped Auckland's Rochelle Coster, who won the 100m on Friday, by 0.02sec in perhaps the race of the weekend.
● World University Games gold medallist Angie Petty, of Canterbury, did the senior women's 800m and 1500m double for the fourth time in the past five years.
● Hamish Carson, of Wellington, dominated the senior men's 1500m to win in 3min 44.42sec.
● 2010 Commonwealth Games silver medallist Stuart Farquhar, of Waikato, won the senior men's javelin. His 77.77m best was on his first attempt, but the wind picked up and he could not better it.
● Canterbury para runner William Stedman (16), who had already qualified for the T36 400m in Rio, qualified for the 800m, despite having run the distance only once before. Stedman won in 2min 12.27sec, 0.20sec inside the qualifying mark.
