Melbourne Victory started its AFC Women's Club Championship campaign with a 4-0 loss to Incheon Hyundai Steel Red Angels on Tuesday.
First-half goals from Kim Dam-bi and Thais Guedes put the WK League champion in control at Yongin Citizen Athletic Park Stadium.
It sealed its win in the second half thanks to a brace from Lee Se-eun.
Victory made a bright start and Melina Ayres fired a shot over the crossbar after Lia Privitelli did well down the right in the 10th minute.
Jeff Hopkins' side was close to going ahead eight minutes later when Ayres and Natasha Dowie combined.
Ayres played in the forward and Dowie's fine low effort was heading for the bottom corner before a diving save by Incheon goalkeeper Kim Min-jeong.
Instead, Incheon struck twice to take a 2-0 lead into half-time.
Kim poked past Victory goalkeeper Casey Dumont in a one-on-one before Thais tapped in from close range in the 33rd minute.
After Dumont denied Jung Seol-bin, Incheon scored twice in the space of two minutes through Lee.
Lee curled in a brilliant 25-yard free-kick before then finding the bottom corner from inside the area to make it 4-0.
As the tempo slowed, Victory almost pulled a goal back late, but Grace Maher's 20-yard effort was superbly saved by Kim.
AFC Women's Club Championship 2019 Match Day 1
Melbourne Victory 0
Incheon Hyundai Steel Red Angels 4 (Kim Dam-bi 24', Thais Guedes 33', Lee Se-eun 57'/58')
Victory will face Jiangsu Suning on Thursday.