'Really proud of you': Former partner's touching moment with Ash Barty

Ash Barty’s friendship with fellow Aussie Casey Dellacqua is proving one of tennis’ most enduring and heartwarming relationships.

As the World No.1 booked her spot in the second round with a commanding straight sets win on Wednesday, it was fitting that Dellacqua was right there at her side.

'WHAT THE HELL': Reporter's 'embarrassing' Ash Barty gaffe in live interview

'OH MY GOD': Nick Kyrgios loses it over reporter's bizarre banana question

'HAVE A HEART': Reporter's 'cruel' question brings Australian Open teenager to tears

The former doubles partners have played plenty of tennis together, forging a strong friendship over several years on the professional circuit.

Barty has often credited "best mate" Dellacqua with much of her own success, with the 23-year-old carrying the hopes of a nation as she looks to end Australia’s 42-year title drought at Melbourne Park.

Dellacqua, who hung up her racquet in 2018, was on hand to provide commentary during Barty's second round match on Wednesday.

The pair then provided fans with a lovely insight into their friendship as a clearly nervous Dellacqua interviewed the World No.1.

"So much has changed for you obviously, but you haven't changed, you are still the same Ash," Dellacqua marvelled after watching Barty’s impressive second round display.

"I don't know why I'm shaking talking but I'm really proud of you.

"So much has changed for you but you're still the same except you look on Pinterest a little bit more, looking for options for your beautiful new house that you're building."

Barty said that while the new house was keeping her mind off tennis at times, she admitted that looking at ways to kit it out online was proving quite “dangerous”.

"I'm going to have to keep working pretty hard to make sure that I can afford this thing but it's going to be fun, it's going to be exciting, I can't wait," Barty enthused.

Casey Dellacqua provided a lovely interview with Ash Barty on day three of the Australian Open. Pic: Getty

For now though, Barty’s focus will be on tennis and her third round match at Melbourne Park.

A three-set comeback winner in the opening round, top-seeded Barty needed barely an hour to see off big-hitting world No.48 Polona Hercog 6-1 6-4 on Wednesday.

Unlike Monday night when she dropped the first set against Lesia Tsurenko, a switched on Barty dominated the opener in windy conditions on Rod Laver Arena, twice breaking Hercog's serve.

The Slovenian put up more of a fight in the second, forcing Barty to hold from double-break-point down in the eighth game .

Gusty conditions no problem for Barty

The world No.1 then gained a decisive third service break the very next game before closing out the contest, again from 15-40, in 66 minutes with four straight clutch first serves.

"It's been another clean match today and very happy to get out of that one," Barty said finishing with five aces, 16 winners, 16 unforced errors and saving all six break points she faced.

"It was different, end to end. The wind played a factor, particularly with the new balls.

"Polona has the ability to play off the court. It was about making as many balls as I could and, once I got my opportunity, I could take it."

Barty next plays in-form Kazakh Elena Rybakina, a winner of this month's Hobart International, or Belgian qualifier Greet Minnen on Friday for a place in the last 16.

Should she win, Barty will run into either her Open doubles partner Julia Goerges or American world No.19 Alison Riske in the fourth round.

Goerges upset 13th seed Petra Martic 4-6 6-3 7-5 earlier on Wednesday, while Riske - who ended Barty's 15-match European winning streak last year at Wimbledon - hammered Zhu Lin 6-3 6-1.

To stay on top of Australian Open news follow us on FacebookTwitter and Instagram (@yahoosportau).

With AAP