|ICC World Twenty20 Group A, Dharamsala:|
|Ireland 154-5 (20 overs): Wilson 38 (34), Ansari 3-37|
|Oman 157-8 (19.4 overs): Aamer 32 (17), Maqsood 38 (33)|
|Oman won by two wickets|
|Scorecard and standings|
World Twenty20 newcomers Oman stunned Ireland with a two-wicket victory with two balls to spare in their first game.
Chasing 155, Oman openers Zeeshan Maqsood and Khawar Ali added 69 and, after a collapse of 4-21, Aamer Ali hit 32 from 17 balls in Dharamsala.
With 14 needed from the final over, Max Sorensen bowled two no-balls, one of which went for four and another which went for four byes to end the match.
Earlier, pace bowler Munis Ansari took 3-37 as Ireland made 154-5.
Ireland, playing in their sixth World T20 and used to causing upsets, were given a taste of their own medicine by the lowest-ranked team in the tournament.
Ireland must now beat Bangladesh and the Netherlands to have any hope of topping Group A and claiming one of the two places available in the main draw.
The shockers are shocked
While Ireland's score seemed adequate on a slow pitch, the inaccuracy of their pace bowlers - perhaps partly caused by a damp ball in dewy conditions - was brutally punished by the aggression of Oman openers Maqsood and Khawar.
However, when both played on off Kevin O'Brien, Oman slipped from 69-1 to 90-5.
The chase was taken up by Aamer, who took three successive fours off a Tim Murtagh over that included two no-balls and a wide and cost 20 runs in total.
Even then, after some wonderful athletic fielding by Gary Wilson that saved five runs and a 19th over from Boyd Rankin that went for only four, Oman looked second favourites.
In the final over, Sorensen's first delivery - called a no-ball on height - was helped for four by Aamer, who was then given caught behind despite replays showing he had made no contact.
Off the next ball, with three needed from two deliveries, Sorensen bowled another high no-ball that went through the legs of wicketkeeper Niall O'Brien and away for the winning runs.
A tale of two fielders
Ireland looked to have been put back on the right track by the brilliance of Wilson, whose gravity-defying leap and stretch on the mid-wicket boundary denied Aamer a certain six.
However, his effort did not change the game as much as the brilliant catch from Maqsood which gave Oman their first wicket.
Fielding at short cover to the left-arm spin of Aamir Kaleem, Maqsood jumped high to his left to cling on one-handed to a Paul Stirling drive.
That ended an opening stand of 48 that was just gathering momentum and, from there, Ireland were never able to break free.
All of Oman's batting, bowling and fielding belied their lowly position in Division Five of the International Cricket Council's World League, four tiers below the one-day international status enjoyed by Ireland.
Oman's attack was led by the slingy Ansari, who bowled top-scorer Wilson for 38 and removed both O'Brien brothers as Ireland failed to find the late impetus that might have put them out of reach.
He was backed up by the skiddy left-arm spin of Ajay Lalcheta, who began the innings with a maiden and conceded only 24 runs from four overs.
Oman reached this event by winning the 2015 Asian Cricket Council Cup and then coming through a World T20 qualifier, when former England all-rounder Derek Pringle was hired as a technical advisor.
Now, in their first game in an ICC global event, they have shocked arguably the most successful and well-resourced nation outside Test cricket.
What they said
Ireland captain William Porterfield: "It's still in our hands - we've got to go back, regroup, win two games and give ourselves a chance.
"The dew was a little slippery but we're not going to use that as an excuse."
Oman's man of the match Aamer Ali: "We were trying to get boundaries every over. We have done a lot of hard work before coming to the World Cup, and finally it has paid off."
Ireland play Bangladesh on Friday (14:00 GMT) knowing that defeat will send them out of the tournament. Oman will look to repeat their heroics against the Netherlands earlier on the same day.