The Las Vegas Aces became the first team in more than 20 years to repeat as American Women's National Basketball Association (WNBA) champions after holding off the New York Liberty 70-69 in Game 4 of the Finals on Wednesday.

A'ja Wilson, named the Most Valuable Player (MVP) of the Finals, produced 24 points and 16 rebounds to help the Aces recover from a 12-point deficit in Brooklyn.

New York had appeared on track to keep their first Finals campaign in 21 years alive, with guard Courtney Vandersloot leading with 19 points, but an error-filled second half cost them dearly.

"We fought through so much adversity during the season, and we just kept the main thing the main thing," said Wilson.

"We cried together, prayed together, and now we are popping champagne together."

The Aces were out of sync early on with starters Chelsea Gray and Kiah Stokes sidelined due to injury and coughed up eight turnovers in the first quarter.

New York had a commanding lead at halftime thanks to standout performances from forward Betnijah Laney and Vandersloot, but Las Vegas came alive in the third, outshooting the home team 23-12.

A clutch jump shot from Sabrina Ionescu put New York within one point with only seconds left but their frantic last-gasp attempts to clinch victory came up short.

"Credit to Vegas, they were down, they found a way," New York coach Sandy Brondello told reporters. "We fought but it wasn't our best game today."

Dubbed the league's 'super teams', the two sides had been on a collision course to the Finals, attracting enormous interest from fans in the best-of-five series.

"There were a lot of years that we weren't so super, but you can't build a super team in a couple of months," said Aces guard Kelsey Plum, who had seven points, eight rebounds and five assists.

"It takes years and I'm just really proud of this group."