World number one Simona Halep crashed to a straight-sets defeat against unseeded Ashleigh Barty in the second round of the Sydney International on Wednesday. Halep, playing in her first tournament since a back injury cut short her 2018 season, lost 6-4 6-4 in 87 minutes with the result dealing a blow to her Australian Open preparations. Australian Barty, who is ranked 15th in the world, fired 26 winners and won four out of seven break points as she recorded her first victory over a reigning world number one. The 22-year-old Barty faces either Elise Mertens or the winner of the first round clash between Anett Kontaveit and Monica Puig in the quarter-finals.