The 23-year-old Decathlon Ford team rider positioned herself near the front throughout in the opening 2025 race in Araxa, Brazil.
She held off Switzerland’s Nicole Koller, a former world champion on the road, and American team-mate Savilia Blunk in the sprint finish.
It followed Maxwell’s second placing in the short-track race the previous day.
The previous cross-country best by a New Zealand rider was a second by Olympian Rosara Joseph 17 years ago in Australia.
Maxwell, the under-23 world champion, is competing in her first full UCI world cup season as an elite rider but made her mark at the highest level with her eighth at the Paris Olympics.
Her ranking gave her a front-row start, using her pace to move into the front group.
She led after the first full lap but dropped 12sec behind the leader mid-race before using her climbing ability to move to the front.
She made her move with two laps remaining, putting in a scorching lap to open an 18sec advantage.
The New Zealander maintained her calm as the rivals flew at her over the final lap, finishing 4sec clear of her chasers.
Maxwell was overwhelmed with the performance and praised her Decathlon Ford professional team.
“It has not sunk in," Maxwell said.
“It’s the little things. On Monday we did media and they wanted a celebration pose. I thought, well, that won’t get seen, so it won’t matter what I do. And here it is on the social posts.
“The team manager said it was going to be a hot race, super punchy climbs, so to stay in the bunch and with two to go, do what you want.
"Coming into the feed zone with two laps to go, he looked at me and said, ‘Now you go on the climb.’
“I’ve been working super-hard on technical skills on downhill. So, I thought if I could get to the front and attack, and if I can get 10 seconds gap, that is a big time to make up.
“I can’t believe it worked. I can’t wait to watch the race.
“The team has been so incredible to me. I’ve had a hard time the last two years with my health and the team stood by me. So, to have everything fall into line for these amazing people is the most special part."
Maxwell remains in Brazil for the second round on the same venue with the course reversed.
There was a solid return to the world cup for New Zealand and Oceania men’s champion Anton Cooper, who finished 36th in the elite race.
The Lapierre Racing Unity rider, who had a year out of the sport with illness, started off the sixth row and gradually found space to move forward, finishing with one of the fastest laps in the field.
In other racing, national champion Marie Laurie was 26th and fellow Christchurch rider Annabel Bligh 31st in the under-23 women’s race.
— APL
