In front of a roaring Sydney crowd, the top seed Australian took the match 6-4 6-4 to take her first win over the Romanian. 

Entering the game, Barty had never taken a set from the current world no.1 in their previous four encounters. 

"I knew Sim would be a little bit rusty, being her first match of the year and first match in a while," Barty told media after the match.

"Very happy with the way I was able to keep it kind of together."

Despite battling gusty and hot conditions on centre court, the Queenslander drew first blood in the match after breaking Halep for the second time in the set and was able to hold the lead.  

In the second, it appeared as though the Romanian was in control taking the first break but unfazed by the reigning 2018 French Open winners advantage Barty broke straight back. 

The world no.15 played aggressive tennis hitting 26 winners while Halep was unable to overcome the windy conditions to finish with 22 unforced errors.

Barty will take momentum from back-to-back wins over the last two French Open winners as she heads to the quarterfinals of the Sydney International.