Australian Alanna Smith has come up with some clutch defence to keep her Minnesota Lynx alive and force a deciding game five in the WNBA Finals against New York Liberty.

With scores tied at 80 in the final 30 seconds, Smith was given the job of defending two-time MVP Breanna Stewart as she sought the potential series-winning shot for New York.

Picking her up near half-court, Smith stayed in front of the 2018 and 2023 Most Valuable Player and not only forced her into an awkward running jump shot, she pressured Stewart into missing the rim completely, forcing a shot-clock violation.

Bridget Carleton made two free throws with two seconds left at the other end and the Lynx beat the Liberty 82-80 to set up a deciding game five in New York on Monday morning (AEDT).

It is the first time the WNBA Finals have gone the distance since 2019, when Washington topped Connecticut.

"Last 40 minutes of the season could be anywhere, we're going to be out there going to war and I'm pumped," said Kayla McBride, who led the Lynx with 19 points.

Smith scored 12 points on 5/9 shooting, including hitting both shots from three-point range, while pulling down seven rebounds, blocking one shot and getting two steals.

It was a remarkable effort considering the Opals forward carried a back injury into the game.

Lynx coach Cheryl Reeve is no stranger to winner-take-all games. She coached Minnesota in three straight from 2015-17, winning two.

"I don't think about the other ones," Reeve said.

"I feel very blessed in my career to have a chance to been a part of so many. I haven't won them all. … What I'm thrilled about is that this group gets to experience the game five."

Unlike the first three games of the series, when one of the teams built a double-digit lead, this one was tight throughout with 14 lead changes and 13 ties, and neither team leading by more than six.

With the game tied at 80 with 18 seconds left after Smith's defensive play, Lynx guard Courtney Williams dribbled to run the clock down and missed a jumper with a few seconds left, but Carleton got the rebound in the lane and was fouled by Sabrina Ionescu as she tried to fling the ball back toward the basket.

The 27-year-old Canadian calmly made both free throws, and Ionescu was unable to duplicate her heroics in game three, when she made a 28-footer with a second left to give the Liberty a 2-1 series lead.

Minnesota stands one victory away from a record fifth WNBA title, which would break a tie with the Houston Comets and Seattle Storm.

The Liberty are looking for their first title and have lost in the finals five times. The team was one of the original eight franchises when the league began in 1997 and is the only one left of that group not to have won it all.

AP/ABC