Alexandre Lacazette scored on his Arsenal debut as the Gunners dispatched Sydney 2-0 victory in front of a packed out Allianz Stadium.
Per Mertesacker was also on the score sheet, while Danny Welbeck missed a penalty before a host of changes were made in the second half.
Reiss Nelson, 18, grasped his chance to impress Arsene Wenger though, producing a scintillating display to announce himself as one of the club's future stars.
The victory sets the Gunners up nicely for their second game against Western Sydney Wanderers on Saturday.
Here's our man John Cross with his player ratings from the Allianz Stadium in Sydney:
Cech 6 (Martinez, 46, 6)
Decent save mid-way through the first half after Mertesacker let his man drift.
Bielik 6
Comfortable if unspectacular, had two headed chances from corners.
Mertesacker 7
Impressive finish for the first goal and marshalled his defence well.
Kolasinac 7
A solid start to his Arsenal career. He linked up well with Cohen Bramall.
Nelson 8
A brilliant performance from the 17-year-old. Cut in well from the right flank to create numerous chances for himself and others. Looks a real prospect.
Coquelin 7
Did a good job of breaking up attacks before they began, prevented Sydney from entering Arsenal's half for most of the first 45 minutes.
Willock 7
A lively performance from the only Willock brother remaining at Arsenal. Unlucky not to score following an impressive run.
Bramall 6
Not tested defensively but showed good energy getting forward.
Ozil 7
Set the pace early on and was Arsenal's go-to man in possession.
Walcott 6
A lively start and some decent runs but, unfortunately, no end product.
Welbeck 6
Got into good positions but struggled to score. His poor penalty was saved easily.
Ten subs in the 68th minute: Lacazette, Giroud, Oxlade-Chamberlain, Iwobi, Monreal, Xhaka, Maitland-Niles, Elneny, Malen, Nketiah.