Konta was forced to rally from a set down for the second time in two days as she battled back to beat a spirited Tomljanovic, eventually prevailing 4-6 6-1 6-4.
Britain’s number one arrived in Brisbane on the back of a miserable run of form that had seen her fail to win a match since August. But she has started 2018 promisingly having teamed up with a new coach, Michael Joyce, at the beginning of December.
“To be honest, it's a great thing to have two tough matches early on,” Konta said on-court after the match. “It's a boost, the match fitness, and it boosts a lot of the competitive scenarios that we're going to face the whole year. I'm sure my next match will be the same.”
Konta appeared to be feeling the effects of Monday’s battle against Madison Keys at the start of her second round match and Tomljanovic was able to break her serve no fewer than four times in the opening set.
The 24-year-old Croatian, currently ranked 118th in the world, was able to take the first set when she held for just the second time in the match herself, but struggled to match Konta’s firepower in the second.
The 2017 Wimbledon semi-finalist clicked into gear to take the second set 6-1 before a slight wobble in the third, when she allowed a 5-2 lead to slip to 5-5. But she held her nerve in the clutch to win in two hours and 26-minutes.
“It was a tough match - Ajla came out playing well, especially in that first set, and it took me a little bit of time to find my rhythm,” Konta said.
“She made that very difficult, so that's a credit to her and she played incredibly freely at the end of the third set. There wasn't a lot in it so I'm very happy to have just stayed tough and just come through that.”
Tomljanovic, who had her boyfriend Nick Kyrgios watching in the stands, meanwhile added that she was pleased with her performance.
“I thought I played my first round really well. I was probably a little more nervous for that one just because it was the first one,” she said.
“Coming up today, I expected to play well because I've been training well. I've had good wins over the last couple of months, going deep into tournaments, even though they're not the same level like here.
“I've got nothing to be sad about. I'm disappointed just because I obviously wanted to win, and I love playing here. Looking ahead, I'm just pleased with where my game is going, and just hopefully I stay as healthy as possible.”
Konta will now play either Ana Konjuh or third-seed Elina Svitolina for a place in the semi-finals of the tournament.
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