Antrim and DIT will contest next weekend's Bord na Móna Walsh Shield final after wins over Laois and Westmeath respectively this afternoon.
At Rathdowney, Antrim were forced to dig deep before carving out a 0-18 to 0-17 win after extra-time over the hosts.
An 85th minute Neil McManus (0-10) point was the difference in a game where the sides were level on 12 occasions, including 10 times in normal time.
Scores from Tommy Fitzgerald and Stephen Maher (0-6) gave Laois an 0-8 to 0-6 interval lead, which they extended to five points by the 43rd minute.
However, Antrim took a 0-13 to 0-11 lead in the 55th minute, with seven unanswered points, three from McManus, with Darren Hamill, Neal MacAuley, Paddy Doherty and Kevin Barry McShane also on target.
Laois led by a point approaching injury-time following a Willie Hyland sideline cut, but a late Matt Donnelly score forced extra-time.
The sides were tied twice in extra-time, but Antrim dug deep as McManus claimed the winning score.
DIT claimed a 3-13 to 2-5 win over Westmeath in the other semi-final at Lakepoint Park, Mullingar.
Goals from David Treacy, Michael Maloney and Finn Dunleavy helped pave the way for victory in a game where DIT always looked likely winners.
DIT led by 1-3 to 0-0 early on following Treacy's goal and built up as 1-7 to 1-2 interval lead, with Derek McNicholas netting for the hosts.
DIT continued to be in command for the majority of the second half, with Conor McCormack, Maloney and Cian O'Brien impressing for the students.
Maloney and Dunleavy added a goal each for the students in the third quarter, with Westmeath's second goal coming too late after Niall O'Brien finished a scrambled effort to the net.