The skipper needed to score from the dead-ball play, some 20 metres out, to give her side any hope of a grand final berth.

She did just that, and then when the preliminary final seemed destined for a penalty shootout between United and Canberra Croatia FC, she made sure it would not come to that.

The No.9 headed home the winner with one of the final plays of the game in the 5-4 contest on Sunday night to book her team a grand final ticket.

"I was like, 'Don't miss it'. There was so much pressure but I felt like it was better it was me feeling that than anyone else because if I missed [the free kick] I was going feel a crappy. But it was within my range and I was pretty confident," Backhouse said.

"Then the corner, it was just dropping for me. And I was like, 'Come on, just a little skim and it's in'. But I was lucky that it came off at the right angle and got a deflection.

"But I'm so proud. We have quite a young team, and they are such core players in our team and they showed great maturity for such young players today. So I'm really excited for the future of Belco."

United ran away with a 3-0 lead in the opening minutes, before Croatia clawed its way back to 3-3 to force the preliminary final to extra-time.

It began with rapid fire United strikes, three goals in five minutes for Belconnen catching the minor premiers by surprise.

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The first came 13 minutes into the fixture. Sofia Palywoda sent a long ball over the top on a counter-attack to catch Croatia's defence flatfooted.

Keira Bobbin's pace proved no match for her counterparts, allowing her to go one-on-one with goalkeeper Natasja Vasta. But Croatia's goalkeeper slipped as she rushed out and Belconnen went 1-0 up.

Belconnen's next came three minutes later. Reilly Yuen played Bobbin in again, utilising her pace once more, and with all of Croatia's eyes on her sent a cross into the mix for Palywoda to double the lead to 2-0.

A mere two minutes later and Croatia found itself staring down a 3-0 scoreline.

Bobbin was involved again and sent a cross in from the right, finding her teammate Backhouse to help it along for a first-time strike by Olivia Bomford to make it 3-0.

It took until the 28th minute for Croatia to respond and get on the scoresheet.

An awkward bounce onto a Belconnen hand in the box gave Brittany Palombi a chance from the penalty spot, and she made no mistake to lessen the deficit and get her side on the scoreboard at 3-1.

Croatia showed why it went undefeated for 19 rounds this season, and clawed another back six minutes into the second half to make it 3-2.

Central defender Rhiannon Fensom went long, taking Belconnen's defence by surprise to allow for a stray first touch in the box. Croatia's striker Sienna Birnie pounced on it and made it a one-goal game.

Palombi's cross, a decoy run to the near post by Grace Gill, and one of the first touches by substitute Shania Settin at the back post, levelled the score at 3-3 in the 78th minute.

And that was where it stayed to force the game into extra-time before Croatia scored seven minutes into the first extra period at Riverside Stadium to break the deadlock and take the lead for the first time.

A throw-in deep in Croatia's attacking corner allowed Gill to get a cross into the box, and while Murphy got a hand to it, Jennifer Bisset got the second effort to make it 4-3.

It seemed as if Croatia had shaken off its demons from last weekend's 5-3 loss, where its comeback sent the qualifying final against Canberra Olympic FC to extra-time before it ultimately fell by two.

But Belconnen was not done yet, despite having seven players fresh off a week representing the ACT at the National Youth Championships.

Backhouse pointed to the older players trying to guide them and instil calmness when they went a goal down in extra-time.

"it just so hard because we do have such a young, new team. So that experience and that maturity comes with time to not stress out about it. And just focusing on the football we know we can play," she said.

"We explode, though, because of that. We do come out strong in that first 15 because of the young girls and it worked out for us today."

The equaliser came in the 118th minute. Backhouse sent the free kick over the wall, and into the back of the net to level it 4-4.

Both sides seemed resigned to a penalty shootout before Belconnen reclaimed the lead again. Bomford swung a corner in before their skipper made it 5-4 with a header.

United will rest and regroup before preparing for its next battle against Olympic in the NPLW grand final next weekend.

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