Antrim recorded their first win in the Leinster SHC, thanks to a hard-earned three-point victory at O'Moore Park.
The Saffrons trailed by 2-7 to 1-5 at the interval, with Neil Foyle and Willie Hyland netting Laois' goals.
Antrim were reduced to 14 men following a straight red card for Neil McAuley in the 40th minute but overcame their numerical disadvantage.
Dinny Cahill's side were stronger in the second half with Neil McManus (0-10) leading their charge.
Laois were dealt major blows before the start of this game with both Brian Campion and Ger Reddin failing fitness tests and having to be replaced by Brian Smith and Noel Costelloe.
Antrim were also forced to make a late change with Simon McCrory introduced to the Saffrons attack instead of Shane McNaughton.
McCrory's inclusion on the Antrim starting line-up proved to be of worth early on, as the St John's attacker planted the ball in the Laois net in the sixth minute for Antrim's opening score.
Laois cut the deficit to a point at the end of the opening quarter, following scores from James Walsh and Willie Hyland, but both teams rued missed opportunities.
The O'Moore's made amends for their poor shooting as Hyland and defender Matthew Whelan slotted over pointed frees to give them a 0-5 to 1-1 lead after 23 minutes.
McManus tied the game with Antrim's first score in 15 minutes as Laois gained a foothold in the midfield sector.
Foyle's 25th-minute goal then gave Laois a 1-5 to 1-2 advantage.
Antrim cut the deficit to a point following scores from McAuley and Karl Stewart, before Hyland netted Laois' second goal from a 20-metre free on the stroke of half-time and another Hyland point put the home side five ahead at the break.
The Saffrons outscored Laois by nine points to two in the third quarter as they claimed a 1-14 to 2-9 lead.
Ciaran Herron, McManus and Karl Stewart all impressed with points, as the visitors braved the dismissal of defender McAuley with 30 minutes remaining.
Laois battled back thanks to an Owen Holohan goal 13 minutes from the end, but Antrim bossed the closing stages.
The Saffrons claimed six of the final nine points with corner forward Conor McCann most impressive with three points from play.
Antrim will now face Wexford in the quarter-finals in a fortnight's time.
Laois: P Mullaney; J A Delaney, B Smith, B Stapleton; J Fitzpatrick, M Whelan (0-2,2f), B Galvin; J Walsh (0-1), S Bourke (0-1); B Dunne, N Costelloe, W Hyland (1-4,4f); O Holohan (1-1), N Foyle (1-1), J Brophy. Subs: C Dunne for Fitzpatrick h-t, W Dunphy (0-2) for Dunne 38, S Dollard for Costelloe 61.
Antrim: C O'Connell; C McGuinness, A Graffin, K Molloy; N McAuley (0-1,1f), M Herron, C Herron (0-1); P Shiels, B McFall; S McCrory (1-0), K Stewart (0-4), J Black; C McCann (0-4), N McManus (0-10,7f, 1 65), K McKeegan. Subs: M Armstrong (0-1) for Black 43m, D Hamill for McKeegan 57m, K McGourty for B McFall 67m,
Referee: Alan Kelly (Galway)