Barty, whose current world ranking is a career-high 15, appeared to be in peak physical shape around the court in outplaying Ostapenko at the Ken Rosewall Arena. 

The match was played in brilliant sunshine, which was in stark contrast to the first two days of the tournament, where rain interrupted play. 

Barty said her preparation had been good leading into the opening match of her 2019 campaign and if she executes better than she had in her two previous encounters against the world's number 1 ranked player in Simona Halep, then she'd have to be a chance of winning.

"I was in both of those matches, I let my opportunity slip, so I know if I do the right thing I'll get my opportunities and then [it] comes down to execution and trying to do the right thing," she said.

"She's the ultimate competitor, she's the best in the world and there's no one better to come up against." 

The Australian was dominant against Ostapenko early and quickly established a 3-1 lead before the Latvian fought back to counter break Barty's serve and take the score to 4-3. 

The score fluxuated a number of times between deuce and advantage during the next game before Barty finally won it to take the score to 5-3.

She quickly closed the set out while on serve to go to a 6-3 lead.   

​Ostapenko hit back on serve in the first match of the second set with a sequence of powerful shots, the last being a beautiful Barty had no answer to for a 1-0 lead, but Barty replied with a great service game of her own to take the score to 1-1.

Barty won the next two games to take the score to a 3-1 lead.

Ostapenko was outplayed on the day, but she showed heart to get herself back into the contest and she won three out of four games, including her next service game to take the score to 4-3.

Barty, last year's finalist at the Sydney International, quickly countered after that and won the next two games to run out as deserved victor with her 6-3 6-3 scoreline.

During the match, Barty appeared sharp and executed well, while Ostapenko showed glimpses of her former 2017 French Open winning self, but her play let her down all too frequently, as it was punctuated with unforced errors and double faults during crucial times of the match. 

Ostapenko will now continue with her Australian Open preparations while Barty awaits her next match against Halep.