While the top-seeded home team stuttered to a four-wicket victory over Kenya with five balls to spare, the Netherlands coasted to a comfortable five-wicket success over Scotland with 12 balls remaining.
In the third and fourth-place play-off later today, second-seeded Kenya will take on third-seeded Scotland while Ireland and the Netherlands will meet in the final on Tuesday at 1300 (local time)
The finalists of the Belfast event are guaranteed a place in the 12-team ICC World Twenty20 2009 to be staged at Lord"s, The Oval and Trent Bridge next year but the inclusion of the third-place team for next year"s event is dependent on Zimbabwe Cricket"s Board ratifying a decision taken by its officials during ICC Annual Conference week, to step back from the tournament.
If Zimbabwe does confirm it won"t play, the top Associate from the Belfast event will take Zimbabwe"s place in Group A (with India and Bangladesh), the losing finalist will ease into Group B (with England and Pakistan) and the third place side takes a position in Group D (with South Africa and New Zealand).
However, if Zimbabwe opts not to ratify its earlier decision to step back from the tournament, the top Associate will join England and Pakistan in Group B and the losing finalists will form Group D with South Africa and New Zealand.
The semi-finals results means the ICC World Twenty20 2009 will certainly have two new teams in the competition while one or maybe both of the previous two participants – Kenya or Scotland – may miss out.
After taking the hardest possible road to the semi-final stage thanks to a last-gasp win over Bermuda on Sunday, Ireland bowled beautifully to knock the second-seeded African side over for 67 in 17.2 overs. But the home team"s batsmen made heavy weather of the small target before achieving success with five balls to spare.
Ireland was cruising nicely at 41-2 in 11.3 overs before it lost three wickets in six balls to slump to 44-5 which soon became 49-6 in 15.4 overs. At that stage, Kevin O"Brien (17 not out) played a little gem of an innings to ensure the top-seeded team avoided defeat.
“I am delighted at our achievement. It"s a great feeling to have qualified for next year"s tournament," said Ireland captain William Porterfield.
“I still remember the dressing room atmosphere after our third defeat (in the ICC WCL Div.1 in Nairobi) and we wanted to avoid that situation this time. Kenya is always a tough opponent but we played really well to win the semi-final.
“I think the conditions for batting are slightly difficult and even though we have depth in our batting, we have struggled to win our matches convincingly despite chasing small totals. But we are improving and I am sure we will arrive in England next year as a much improved side," Porterfield said.
Earlier, Porterfield won an important toss and the bowlers justified his decision by bowling to a teasing line and length with controlled accuracy.
That accuracy of the Ireland bowlers can be judged from the fact that four Kenya batsmen were clean bowled, openers Morris Ouma and Kennedy Otieno were smartly caught off leading edges while Nehemiah Odhiambo and Steve Tikolo were trapped in front of the wicket playing across the line.
All-rounder Andre Botha led the Ireland bowlers charge and finished with figures of 3-20 while Alex Cusack, Kevin O"Brien and Peter Connell shared six wickets between them. Botha, who later chipped in with a valuable 22, was declared man of the match.
In the second semi-final, man of the match Ryan ten Doeschate produced a fine all-round performance to inspire the Netherlands" to an easy five-wicket win over Scotland.
Essex"s ten Doeschate grabbed 3-23 to peg Scotland to 107-8 in 20 overs after Kyle Coetzer (40) and Ryan Watson (22) had provided their team with a 54-run opening start, the highest first wicket partnership of the tournament so far.
Scotland did itself no favours in the closing stages of its innings when it could add only 37 runs in the last 6.1 overs while losing seven wickets.
Ten Doeschate, in the target chase, returned unbeaten on 24 from 14 balls with a six and a four as the Netherlands wrapped up with match in 18 overs. Eric Szwarzcyniski (31), Tom de Grooth (24) and Peter Borren (16 not out) also made valuable contributions.
Kenya 67 all out in 17.2 overs (Steve Tikolo 13, Thomas Odoyo 11; Andre Botha 3/20, Alex Cusack 2/3, Kevin O'Brien 2/15, Peter Connell 2/16) lost to Ireland 72/6 in 19.1 overs (Andre Botha 22; Kevin O"Brien 17 not out, Niall O"Brien 11, James Kamande 2-11, Ragheb Aga 2-12, Thomas Odoyo 2-13).
Scotland 107/8, 20 overs (Kyle Coetzer 40, Navdeep Poonia 26, Ryan Watson 22; Ryan ten Doeschate 3/23) lost to Netherlands 110/5, 18 overs (Eric Szwarzcyniski 31, Ryan ten Doeschate 24 not out, Tom de Grooth 24, Peter Borren 16 not out; Richard Berrington 2/22, John Blain 2/24).