Australia's youthful Opals have been forced into a game-three decider by Japan after the reigning Olympic silver medallists scored a 56-55 win in Sydney.
The Opals scored the last four points of the game on Sunday, but Japan held on to level the series going into the final match in Newcastle on Tuesday.
Australia scored the first nine points and led 13-2 in the first quarter, but both sides defended tenaciously and struggled offensively in a low-scoring grind at the Quaycentre.
The Opals shot 30 per cent from the field and 20 per cent from three-point territory, with Japan shooting 28 per cent and 25 per cent respectively, with the two teams combining for just 13 of 56 long bombs.
Forward Sara Blicavs stared for Australia, top-scoring with 16 points and a match-high 12 rebounds.
Young point guard Shyla Heal added some spark off the bench, hitting three long bombs in the second half, finishing with 11 points, as did forward Darcee Garbin.
Guard Tess Madgen and centre Cayla George each dragged down 10 boards to help Australia to a 55-44 rebounding advantage, but between them made just three of 21 from the field.
Monica Okoye troubled the Opals with her inside-outside game, scoring a match-high 20 points in just under 24 minutes, hitting seven from nine from the field, including three of five from long range.
With several of her most established players unavailable due to overseas club commitments, stand-in Opals head coach Cheryl Chambers gave all 11 of her squad court time to give them opportunity to press for a place in the squad for the world championships in Australia later this year.
"Pretty disappointed, our shooting was way off today," Chambers told ESPN.
"I think even our energy at times was a little bit off."
Blicavs scored the first seven points of the game with Australia leading 9-0 and Japan taking almost three-and-a-half minutes and seven field goal attempts to register their first score.
Up 14-6 at quarter-time Australia went five-and-a-half minutes without a field goal in the second quarter, but led 19-17 at halftime.
With their perimeter shooters struggling, Australia got more pay from pounding the ball down inside to Garbin in the third quarter.
The Opals made just two of their first 21 three-point attempts but hit their last three of the third quarter with two to Heal and one to Madgen, to trail 44-42 at three-quarter time.
Reigning WNBL MVP Anneli Maley will make her Opals debut on Tuesday after returning from America, where she had a brief stint with WNBA side Chicago Sky.