in her singles match against XXXXX during the Fed Cup tie between Australia and the Ukraine at the Canberra Tennis Centre on February 11, 2018 in Canberra, Australia.

Ashleigh Barty has played a pivotal role in helping Australia avoid an upset against Ukraine in the Fed Cup on Sunday in Canberra.

With the tie pushed to the deciding doubles match, after Daria Gavrilova dropped both of her singles rubbers, world number 16 Barty had to reignite her successful doubles partnership with Casey Dellacqua to deliver Australia a 3-2 victory.

After winning her two singles matches before the doubles tie, the result means Australia has advanced to the World Cup playoffs in April, putting them one win away from the Fed Cup's top 8 nations, for the first time since 2005.

Dellacqua, who turned 33 on Sunday, celebrated with a 6-3 6-3 win over Ukraine's twin sisters Nadiia and Lyudmyla Kichenok, labeling the win as a career highlight.

“This tops that ... being here at home in Canberra and playing for your country is definitely one of the best moments of my career,” Dellacqua said.

With world number three Elina Svitolina unavailable to compete, Ukraine was led by teenage prodigy Marta Kostyuk on her Fed Cup debut.

After Barty overcame Lyudmyla Kichenok 4-6 6-1 6-4 in the opening rubber on Saturday, Kustyok, 15, upstaged world No. 26 Daria Gavrilova to level the tie 1-1.

Barty was too strong for Ukrainian Kustyok, who has been dubbed the next Martina Hingis, winning 6-2 6-3. But Gavrilova's troubles continued in her reverse singles rubber, with unranked Nadiia Kichenok delivering a shock 4-6 6-2 6-3 victory.

Gavrilova expressed her disappointment in her performance.

“I was crying so much after the match, but I had a cold shower and said ‘Okay, you have to be there for your teammates',” Gavrilova said.

“I didn't have the best singles matches ... to be honest I had two shockers but I've got to learn from this experience.”

An opponent for Australia's playoff match is expected to be announced on Tuesday night.