They will now battle the USA for the gold medal at 5am AEST on Monday morning as they seek to replicate their performance from 2006 when they were crowned FIBA World Cup Champions.

After breezing through their first four games of the tournament, the Opals were forced to fight until the final siren against Spain and trailed by eight points at three-quarter time.

Liz Cambage (33 points, 14 rebounds, four blocks) had enjoyed a battle against the Spanish front court (and the crowd) throughout the game but she was determined not to let this one slip, scoring six quick points to open the fourth quarter.

Katie Ebzery drilled a corner three as well to give the Opals a 9-0 run and then Astor Ndour, Spanish starting forward, fouled out.

Cambage flirted with fouling out herself after a technical but Laura Nicholls fouled out instead for Spain only a couple of minutes later and the visitors were in the bonus with the game tied inside the last 3:30.

Cayla George (nine points, 11 rebounds, two assists) then stepped up, scoring five in a row including a big three-pointer from an offensive rebound to gain the ascendancy and Australia picked up their defensive intensity as well with blocks from Cambage and Jenna O'Hea.

The two combined again on the following possession with O'Hea (four points, two assists) picking up the steal and Cambage finishing a broken play with a lay-up.

That put the Opals up by five and they staved off a Spanish miracle with more lockdown defence, preventing any late three-point attempts as they finished the game with an 8-1 run and a 22-8 final term.

The game did not look like it was headed to a thrilling conclusion after the Opals dominated the first quarter, a trademark of their 2018 FIBA World Cup campaign.

They pushed the pace early, beating Spain in transition even off made baskets and Bec Allen (eight points, two steals) maintained her form from the Quarter-Final with an early three-pointer while Steph Talbot (two points, eight assists) also impressed.

Cambage recorded nine points to quarter-time as well, putting her team up by 15 at one stage before Spain reeled in the deficit with a 9-2 run to ending the opening stanza.

Their defence then tightened up in the second quarter, sending back lay-up attempts by Ebzery (ten points, three assists) and Sami Whitcomb (five points) to hold the Opals scoreless for over four minutes.

Consecutive three-pointers from Alba Torrens then drew Spain level before the home side moved in front right on the half-time buzzer for their first lead of the game.

Ebzery had the response to start the third, scoring the first two baskets including a bail-out shot clock buzzer beater and that sparked an 8-2 run for the Aussies.

Spain were not going away though, answering with an 8-1 run themselves and the crowd was delirious when they went into three-quarter time with an eight-point edge.

Find the box score here.

The Opals will now meet the USA for the first time since the 2014 World Cup Semi-Final when the Americans prevailed by 12 points.

Winners of the past five World Cup's combined, this is the first time Australia and the USA will meet in a FIBA World Cup gold medal game and both teams enter the contest undefeated.

Watch the game live on Fox Sports Australia channel 505 and keep up to date via @basketballaus.

The Chemist Warehouse Australian Opals Schedule for the FIBA Women’s World Cup (times AEST):

September 22: Australia def. Nigeria (86-68)
September 23: Australia def. Argentina (84-43)
September 25: Australia def. Turkey (90-64)
September 28: Quarter-Final- Australia def. China (83-42)
September 30: Semi-Final- Australia def. Spain (72-66)
October 1: Gold Medal Playoff- Australia vs. USA at 5am

Liz Cambage: "That was a very tough game, a very hard fought 40 minutes. Coming into this game, I didn't want to play Spain. I knew the crowd would be crazy, Spain are such a good team but I am happy. We came up with it in the last minute.

Coach Sandy Brondello: "It was a very hard fought game. I'm very proud of our effort, to be down by eight points on Spain's home court and to get the victory, I give a lot of credit to the players and especially Liz but we made plays when we needed to. It wasn't the prettiest game but in the end, win ugly, it doesn't matter as long as you win.

Cambage: I have so much respect for Spain and European crowds, I played at the Czech Republic Worlds and we lost to Czech Republic because we couldn't deal with the crowd- it was too overwhelming. Since I was a kid playing basketball, the boo's and the crowd being against me has always hyped me up, made me want to go harder and made me want to push harder. I just played my game, I'm a passionate player.

Cambage: This is the furthest I've made it at this level. I feel like I've lifted a bit of a weight off my shoulders. My first World Champs was in the Czech Republic eight years ago and that was the worst the Opals had done in about a decade and then my second major tournament was the Olympics and winning bronze was us doing badly. We didn't even medal in Rio, I felt like a curse. But tonight, to get the win, it was such relief. I'm so proud of this team, I love this group, I love Sandy and I love our staff. I'm so proud of the girls and I'm really proud of me.

Cambage: To win the gold medal would mean a lot to a lot of people. All the past Opals are getting behind us and to have Lauren Jackson sending me messages every day, letting me know we can do this means the world to me. To know we have the country tuning in at 5am cheering us on, it means the world to us. If there's one thing I want to do for my country, it's bring home a gold medal.

Cambage: It's what we all dream of as little girls. I grew up watching Penny Taylor and Lauren Jackson win that medal in 2006, go up against the USA in Beijing and Sydney, it's been a battle for all these years but I think we have such a strong group.

Brondello: I played for 18 years as an Opal, I've been coaching in America for a very long time but I don't think I've been in such a loud environment when we're the team they're cheering against. That's great for women's basketball though. It wasn't one of our prettiest games, they took us out of the things we needed to do but we found a way to win. That shows a lot of character about this team- we are a young team but we have a superstar. Liz just continues to impress me, she's a leader of this team. She loves these big moments and was a motivating influence. I'm very lucky to be coaching this team and to have such a great player. Liz and Lauren are on an even keel for me, that's how special she is to our program.

Brondello: It is a big challenge (against the USA) but we are looking forward to it. In any one game, anyone can beat anyone but we have to play at our best and we need all 12 players playing at our best. We've got nothing to lose which is always nice, we'll go out there and give it our best shot and hopefully it's good enough. We'll prepare, we'll get ready and we'll fight.

Brondello: Steph is a great shooter, Sami is a great shooter and hopefully they won't go 3-18 again tomorrow. We need to make more outside shots to help Liz. It was a really tough, physical game. They're the grinding games you get in playoffs and you have to be able to make plays. I said to our shooters, you missed some shots tonight but tomorrow is a new day and you have to stay confident. I know Liz has carried us but to win a Championship you need a team and we need everyone to step up. It was great to see Jenna O'Hea tonight, she gives us a calming influence.

Brondello: The beauty about playing USA is that I know them very well. Knowing and stopping them could be two different things though. It will help prepare us but at the same time, they have so many weapons so we need to put our best game of the tournament forward and I think we can win. We won't be afraid, we will go out there and fight in typical Opals style.