New Zealand coach Mike Hesson was left ruing his side's failure to take their chances after the Black Caps' exit from the Champions Trophy was confirmed on Monday.
Scorecard | Schedule | Stats | Points Table | Teams and Squads
The Kiwis were already on the brink of bowing out after a 10-run defeat by England in a rain-reduced 24 overs per side clash in Cardiff on Sunday.
And their fate was sealed when Sri Lanka beat defending champions Australia by 20 runs in Monday's final pool match at The Oval to join tournament hosts England as one of the two semi-finalists out of Group A.
Against England, New Zealand slumped to 61 for five chasing 170 for victory before a stand of 73 between Kane Williamson (67) and one-day international debutant Corey Anderson (30) got them back on course.
However, both batsmen fell in the closing stages, leaving what had looked like a gettable target just beyond New Zealand's reach.
"I don't know if it was lacking killer instinct," Hesson told reporters in a telephone conference call in Cardiff on Monday.
"In the chase we got ourselves a long way behind. We kept on losing wickets to the new ball, the ball seamed a little bit and we sort of struggled to cope. It wasn't until Corey and Kane got together that we gave ourselves a chance.
"It's a disappointing way to end. It was a big opportunity for us yesterday (Sunday) and we couldn't quite grab it."
Despite that defeat, New Zealand, who beat Sri Lanka by one wicket in a low scoring thriller in Cardiff and saw their match against Australia end in a no result washout, could still have reached the last four.
They needed defending champions Australia to beat Sri Lanka on Monday but by an insufficiently large margin to overtake New Zealand's superior net run-rate.
After Sri Lanka made 253 for eight batting first, Australia had to reach their target of 254 in 29.1 overs to qualify for the semi-finals.
But having failed in that goal, Australia -- who didn't win a match in the tournament -- kept going.
They were 192 for nine when the last-wicket pair of Clint McKay and Xavier Doherty gave New Zealand hope Australia would achieve exactly the kind of narrow victory that would send the Black Caps into the knockout stages by adding 41 for the last wicket.
But the trans-Tasman aid on offer at The Oval ended when Sri Lanka's Tillakaratne Dilshan held a superb caught and bowled chance to dismiss McKay.
And that meant the end of a run which had seen New Zealand make at least the semi-finals of the last four International Cricket Council 50-over world events.
"When Australia ended up bowling first, it was always going to be difficult because Australia chasing, obviously they were pretty committed to trying to chase it in 29 overs," said Hesson.
"I guess you either get there or you blow up.
"Once they ended up batting second, it decreased our chances a lot."
However, Hesson said McKay and Doherty had given his side a glimmer of hope.
"We realised there was a little sniff there. Those two were batting quite nicely but I guess you can't rely on others to do you favours."
Group A winners England will meet Group B runners-up South Africa in Wednesday's first semi-final at The Oval.
Meanwhile Sri Lanka will face Group B winners India in the second semi-final in Cardiff on Thursday in a a repeat of the 2011 World Cup final in Mumbai, which the Indians won.
The final is at Edgbaston, Birmingham, on Sunday.