Tomic may be five years younger, but is vastly more experienced, as a former junior prodigy who swiftly graduated to the senior tour where he has spent four full years and made a few cameos before that.  This is his 20th grand slam, Groth's fifth. This, and Wimbledon, are his two best majors, and he is now into the last 16 at Melbourne Park for the first time since 2012.

"I felt like it was very, very tough. I'm happy I won because it was a very difficult match,"  said 66th-ranked Tomic, the beneficiary of a crucial Groth double-fault on set point in the second-set tiebreak, and having entered the match believing that his return would be the key to the result.

He has played Berdych twice before, both times at the All England Club, but losing both in four sets, including in the second round last year. Said Lleyton Hewitt, who has relocated to the commentary box after his second-round departure against Benjamin Becker the previous night: "[Tomic] will have to play some of his best tennis, but he's not without a shot, that's for sure."

Groth seemed edgy and unsettled in the early stages, but after Tomic had seemed the better player until the second-set tiebreak, Groth had that on his racquet, leading 5-3 with an overdue forehand winner, but double-faulting at 6-5, before Tomic converted his third set point to cement a formidable lead. "That was definitely my chance, I think," said Groth. "I just missed one. I actually was feeling pretty good in that tiebreak."

Noting that, Tomic also hit a double-fault of his own in the breaker. "It's tense, two Aussies playing for a spot in the fourth round."

The only break in the third set came in the fourth game, Tomic not facing a break point on his own and committing just eight unforced errors to 39 in the brisk 103-minute match on Hisense Arena.

For all the ease of his wonderful service motion, the Groth game is all about effort, whereas Tomic is smoother, silkier, seemingly even casual at times. But the enigmatic Queenslander  appears to have a better focus these days, having endured double hip surgery this time last year, and fallen to 124th in the world before winning the Colombian Open by July.

Certainly, much has changed in the 12 months since he was booed off Rod Laver Arena one set after his injury retirement against Rafael Nadal.

The crowd is on-side again, and Hewitt, too, is among those to note greater maturity, improved fitness, and a willingness to engage and learn.

Groth, from a lower starting point, has come a  long way, but could go no further, two days after a tough five-set win over Thanasi Kokkinakis. Still, he has had a fine week, having not won a main-draw grand slam match until last year's US Open, but earning himself almost $100,000 by claiming two.

Tomic, meanwhile has gone up, and down, and is travelling north again, just as a player with his talent should. Groth predicts a tight Tomic-Berdych match, in which an upset would not be nearly so surprising.

"He's playing well." Groth said. "He's beating quality players. We all know how good Bernie is. I think he's one of the best ball strikers. He's so talented. He reads the game so well. I know everyone talks about him being an unbelievable mover, but he reads the game so well. He's going to give Berdych a bit of trouble."

Tomic, who has dropped only one set in three rounds, to 22nd seed Philipp Kohlschreiber, was less than complimentary about his own level against Groth, and a match that was "not tennis", he declared.

"It was just return of serve. So it was like try and get the serve back. I was getting the return back pretty good."

He planned to practice with Hewitt on Saturday, and discuss the tactics he should employ against Berdych. "I'm excited for this next round. Targeting to win, and we'll see."