Ireland won the toss, made a double-strike in the ninth over of Sri Lanka's innings, and took 6 for 44 in their last six overs. But so comprehensively did Sri Lanka win the other portions of this match, that they trounced Ireland by 133 runs, bowling them out for 192 after they had made 325.
This means that Sri Lanka sail through into the Super Six stage of the World Cup Qualifier, along with Scotland and Oman from their group. Sri Lanka will carry forward their points from their big win against Oman. They play Scotland on Tuesday and the winner of that match will pick up two more points for the next round.
Ireland, meanwhile, have been knocked out of contention for the ODI World Cup. They still have one match to play, against UAE, but both those sides have already been ruled out.
For Sri Lanka, Wanindu Hasaranga got his third five-wicket haul in as many matches, while Dimuth Karunaratne brought up his maiden ODI hundred, having made four successive half-centuries in the lead-up.
Both players' places in Sri Lanka's top XI were not secure. While Hasaranga is a T20I star, he had not quite translated that into ODI glory. Karunaratne, meanwhile, had been Sri Lanka's most consistent Test batter of the last five years but had not excelled in white-ball cricket.
This recent run of half-centuries and now this run-a-ball 103 will make Karunaratne a more serious World Cup prospect, while Hasaranga's 5 for 79 puts him at 16 wickets in the tournament - easily the top wicket-taker.
Karunaratne's contribution was arguably more instrumental to the victory. After Barry McCarthy took two wickets in two balls in the ninth over, Karunaratne and Sadeera Samarawickrama built a 168-run stand. This partnership - in which the batters largely picked up risk-free singles and twos and pounced on the loose deliveries, particularly those that were short - forged Sri Lanka's victory. Samarawickrama was dropped on 66, at mid-on, and he went on to make 82 off 86 balls.
Karunaratne and Samarawickrama came together in the ninth over; when they were parted in the 36th, with 216 on the board, a score of more than 300 seemed inevitable. Their attack, which has not conceded 200 so far in the tournament, will go into the Super Six stage as perhaps the best on show.
Even if it had been too little too late - so thoroughly did Karunaratne and Samarawickrama dominate the middle overs - Ireland's late charge with the ball did dent Sri Lanka. They could have made 20 more, Dasun Shanaka said in the after-innings interview, but the lower order was dismissed cheaply.
The top order, though, had got Sri Lanka through once again, and the bowling was dominant enough to make short work of the Ireland chase. Ireland were 57 for 3 in the 11th over, 116 for 6 by the 20th, and essentially never had the measure of the chase.
Aside from Hasaranga's five, Maheesh Theekshana got two wickets, and Kasun Rajitha, Lahiru Kumara and Shanaka took one each. Curtis Campher top-scored for Ireland with 39.