Opals star Alanna Smith has enjoyed arguably a career-best night in the WNBA, leading the Minnesota Lynx to a 77-70 win over the Connecticut Sun.

The two-time Olympian registered 15 points, six rebounds and two assists in her 25 minutes of court time in Minneapolis to help offset an quiet game for Lynx star Napheesa Collier and even the best-of-five semi-final series at one game apiece.

Collier, who scored 80 points in the two-game sweep of Phoenix in the first round, was held to nine points. She led the hosts with 12 boards and five assists, while Courtney Williams top-scored with 17 points.

"We weren't happy with how we approached the first game," said the 27-year-old Australian centre Smith, who played with Williams for Chicago last year.

"I think we played OK, enough to only lose by three. We knew that we had to take it to another level and we had to have each other's backs."

Alyssa Thomas had 18 points, 10 rebounds and seven assists for the Sun, while DeWanna Bonner scored 17 points and Marina Mabrey added 15.

Connecticut will host Game 3 on Friday and Game 4 on Sunday. Then Game 5, if necessary, would be in Minnesota on October 8.

The Lynx never lost consecutive home games this season on their way to a 30-10 record for the No.2 seed in the playoffs, and their 73-70 defeat in Game 1 clearly fuelled a fierce follow-up.

The two best defensive teams in the regular season were on full display in a first quarter in which the first 14 shots misfired and each side had two turnovers in less than four minutes.

Smith, the shot-blocking specialist who is on her fourth team in four seasons, has revitalised her career in Minnesota under coach Cheryl Reeve two years after being released by Indiana. She swished a three-pointer early in the third quarter for a 41-30 lead.

"I believe to be successful you do have to experience adversity ... go through the lumps, bumps, all of that to get through the promised land. That's the only way. If it was easy everybody would be doing it," four-time WNBA champion Reeve said.

Earlier on Tuesday night in New York, Sabrina Ionescu and her Liberty teammates downplayed being on the brink of knocking off the Las Vega Aces.

Ionescu scored 24 points and the home side won 88-84 to take a 2-0 lead in their best-of-five series.

"Being up 2-0 is great, but we haven't won anything," she said.

"Did what we were supposed to do, protect home court. We're not patting ourselves on the back, talking how happy we are. We didn't come to win two games at home and be satisfied, we're a hungry group."

Game 3 is Friday night in Las Vegas, with the two-time defending champion Aces trying to avoid being beaten by the team they defeated in the WNBA Finals last year.

"We protected home court. We want to go to Vegas," the Liberty's Australian coach Sandy Brondello said.

"We play well on the road and they play great at home."

No team has rallied from a 2-0 deficit to win a best-of-five playoff series in WNBA post-season history.

With AAP.