Former multiple Fed Cup champions Australia and Italy needed to power through dramatic ties to advance from World Group II into the World Group Play-offs, and Romania and 2002 Fed Cup winner Slovakia joined them in the winner's circle.

The World Group Play-offs will take place in April, containing these four victorious teams as well as the four losing teams from this week's World Group I ties, to determine who will play in World Group I in 2019.

Here are the final results:

Australia 3 - 2 Ukraine
Romania 3 - 1 Canada (fourth singles not played)
Italy 3 -1 Spain (insurmountable lead)
Slovakia 4 - 1 Russia

Casey Dellacqua celebrates victory. (Getty Images)

Seven-time Fed Cup champions Australia had to go down to the wire to subdue a scrappy Ukrainian team, eventually emerging as 3-2 victors to move into the World Group Play-offs.

Coming into Sunday having split the opening singles, Australia took a 2-1 lead via World No. 16 Ashleigh Barty’s comprehensive 6-2, 6-3 win over rapidly rising 15-year-old Marta Kostyuk.

Read more: Kostyuk’s Australian ‘fairytale’ continues in Fed Cup

But Aussie No.2 Daria Gavrilova was stunned for the second day in a row, as Nadiia Kichenok, currently unranked in singles, rallied for a 4-6, 6-2, 6-3 victory over the 26th-ranked player in the world, to level the tie at 2 matches apiece.

In the end, though, the doubles pairing of Barty and Casey Dellacqua came through for the Australians when needed, as the four-time Grand Slam finalists eased past the sibling duo of Lyudmyla and Nadiia Kichenok, 6-3, 6-4, in 65 minutes. The big match experience of Barty and Dellacqua paid huge dividends as the tie concluded, and they never faced a break point in the match.

Dellacqua celebrated her 33rd birthday on Sunday with the exciting match. “There’s nothing more special being out here representing Australia, especially on my birthday," Dellacqua said to FedCup.com, "and with my best mate, with my team, with my family here, so it’s really special and something I’ll remember."

"For me being a little bit older, not knowing how much longer I will play for, not knowing how many more of these moments that I’ll get...I really appreciated the moment and the experience," an emotional Dellacqua continued.

It was an emotional weekend for Italy, as the four-time Fed Cup champions (all since 2006) moved past Spain, who won five Fed Cup titles during the 1990s.

The tussle between two titans of Fed Cup was at 1-1 coming into Sunday’s matches, and the day opened with a battle between two former Top 10 players. Ultimately, 2012 Roland Garros runner-up Sara Errani claimed victory over recent Australian Open quarter-finalist Carla Suarez Navarro, 6-3, 3-6, 6-3. Each player held 14 break points, but Errani converted more of them by a margin of 10 to eight, to get the win.

That set the stage for a gutsy victory by Italy’s Deborah Chiesa to clinch the tie, winning a dramatic final-set tiebreak en route to a 6-4, 2-6, 7-6(7) win over Lara Arruabarrena. 

Arruabarrena led 4-1 in the final set before Chiesa pulled it back to 4-4. Then, in the tiebreak, Chiesa led 5-1 before Arruabarrena tied it at 5-5. The Italian had a match point at 6-5, but Arruabarrena won two points on serve to lead 7-6, giving the Spaniard a match point.

But Chiesa held firm on serve, getting to 7-7 and then hitting an ace for 8-7 to set up a second match point. The Italian converted that point, and dissolved into tears after a stirring encounter.

2002 Fed Cup champions Slovakia also advanced to the World Group Play-offs, dispatching Russia 3-1 after the singles. The Russians have won four Fed Cup titles, all since 2004, but they were undone by a deep Slovakian squad, whose three wins came courtesy of three different players.

After World No.18 Magdalena Rybarikova squared the tie at one match apiece on Saturday, Jana Cepelova put the Slovaks up 2-1 with a quick 6-4, 6-4 defeat of Natalia Vikhlyantseva, who had won the opening match for Russia.

Viktoria Kuzmova clinched the tie for Slovakia in the fourth rubber, outlasting up-and-coming 16-year-old Anastasia Potapova, 3-6, 6-3, 6-4, in just over two hours. Both players were mentally tough while facing break points, with Kuzmova saving 10 of 11 and Potapova saving 10 of 12. It was the one additional break by Kuzmova that made the difference in the match, and the tie.

“It wasn’t an easy situation for me, but I knew I had to stay focused and positive,” Kuzmova said to FedCup.com. “The situation was made easier by the fact that Cepelova won and we were 2-1 up, so I am really delighted to have clinched the decisive rubber and put us through to the next round.”

Finally, Romania had no problem advancing to the World Group Play-offs. After Sorana Cirstea and Irina-Camelia Begu gave the hosts a 2-0 lead over Canada on Saturday, the Romanians swept to an insurmountable 3-0 lead with a routine 6-2, 6-4 win by Begu over Katherine Sebov.

Begu eased to victory in 85 minutes, breaking Sebov four times and holding all but once, by winning a decisive 76 percent of points on her second serve.

"The tactics were just to play my game, and I did that much better than on Saturday," Begu told FedCup.com after her match. "The team is feeling great, so happy and proud – it was our goal to win after three matches, but really it’s never easy.”

The Canadian doubles team did put one point on the board before the end of the tie, with Gabriela Dabrowski and Carol Zhao knocking off Ana Bogdan and Raluca Olaru in a match tiebreak.