Jersey sealed promotion from World Cricket League Five with a dominant 10-wicket win over Nigeria.
Pace bowler Ben Kynman starred for the hosts with figures of 6-18, helping restrict the Nigerians to 93 all out.
Openers Peter Gough and Nat Watkins reached the target within 15 overs, but then had to wait for news from Guernsey's match against Oman before the celebrations could begin.
Oman's victory means they go through to the final at Guernsey's expense.
"It's been a fantastic day," Kynman told BBC Radio Jersey. "It was all about keeping it nice and straight, nice and full, and today I got a bit of luck with a couple of them and that's what you need some days."
Jersey skipper Gough won the toss and put the opposition in to bat, as early wickets from Anthony Kay (1-19) and Rob McBey (2-21) reduced Nigeria to 39-3 from six overs.
Kynman then took centre stage with a wonderful display of quick bowling, dismissing the bulk of the middle order and tail.
Knowing net run-rate could come into the equation to decide promotion places, Gough (41 not out) and Nat Watkins (50 not out) hit 16 boundaries between them to reach the total with more than 35 overs to spare.
Then came the wait for the calculations and the result from FB Fields, where Guernsey had struggled to 141-8 in their 50 overs.
Oman lost early wickets, slumping to 13-4 before recovering to win by two wickets and top the group with a 100% winning record.
They go through to Saturday's final at Grainville and along with Jersey clinch promotion to World League Four, to be staged in Los Angeles later in 2016.