Jersey all-rounder Anthony Hawkins-Kay impressed with bat and ball but could not save them from a 58-run defeat by Oman in World Cricket League Five.
Hawkins-Kay took of 2-18 as Oman posted a 50-over total of 205-9 in a match abandoned on Saturday because of rain.
He then top-scored with 45 off 61 balls, but Oman's Munis Ansari took 5-27 to skittle the hosts for 147.
"They're the number one seeds and showed why," coach Neil McRae told BBC Radio Jersey.
"We outplayed them on Saturday in a game that was washed out, but this time they got the better of us.
"Unfortunately it wasn't our day, a few things went against us - we're still very confident in the batting order and the quality of this team."
Defeat left Jersey third after two games, having beaten Vanuatu in their opener, and they next face Tanzania on Tuesday.