Zrenjanin, Serbia, 23 April 2017 | AAP

Australia are in the box seat after day one of their Fed Cup World Group II Play-off tie against Serbia, taking a 2-0 lead following singles wins to Ash Barty and Daria Gavrilova on Saturday.

Barty defeated Serbian No.1 Aleksandra Krunic 6-4 6-3, adding to the win she scored over the 24-year-old at January’s Brisbane International.

Later, Daria Gavrilova bagged her first Fed Cup win with a 6-2 6-2 demolition of teenage surprise selection Ivana Jorovic and showed plenty of emotion when the victory was secured.

“It was a great day,” team captain Alicia Molik said. “It really put a smile on my face seeing the emotion after Dasha’s win and what she was feeling because that truly is what it means to her.

“She’s put in a wonderful week of training this week so she deserved everything that was delivered to her today.”

Gavrilova can seal the tie with victory over Krunic in Sunday’s first rubber. The pair have played three times previously with the Serbian prevailing on each occasion but Gavrilova says times have changed.

“It’s a long time, especially for how young we are,” she said. “I feel like I’m more of a mature player and more professional so it doesn’t bother me that my head-to-head is not great against her.

“It’s going to be really tough, she’s a great fighter but I’m feeling pretty confident.”

Barty will partner Casey Dellacqua in the doubles against Krunic and Nina Stojanovic.

“Ash made me really proud today,” Molik said. “I know there were some ups and downs in her match, she was fantastic when it counted the most, on the big points. She brought something special to those moments and I think that’s the sign of a really great player.”

In other World Group II play-offs France and Germany boast a 2-0 advantage over Spain and Ukraine respectively, while the ties between Russia and Belgium and Slovakia and the Netherlands are all locked up at one apiece.

Early on Sunday the Czech Republic had a 1-0 lead over the USA and Belarus and Switzerland were tied at 1-1 in the Fed Cup semi-finals proper.

For more information, visit our dedicated Australia v Serbia Fed Cup tie page.