Willie Hyland struck an injury-time goal to complete an unlikely win for Laois in a pulsating clash in Portlaoise on Saturday.
The surprise setback leaves Clare needing to win their final league game against Carlow to earn a place in the promotion decider against Limerick for that coveted Division 1 place.
With Ger O'Loughlin's Banner men on a four-match winning streak and having run up cricket scores in their two most recent league outings against Down and Kerry, little hope was given to a Laois side that looked to be in turmoil after slumping to a subdued defeat in Down last time out -- their third reverse in five games.
Laois started much the brighter however and an early John Brophy goal set them on their way to a three-point advantage at the interval.
With their promotion hopes looking in jeopardy, Clare hit back in ruthless fashion after the restart and goals from Darach Honan and Jonathan Clancy edged the visitors into a four-point lead midway through the half.
Brendan Fennelly's men fought back, however, and Neil Foyle's close-range goal and a Hyland free restored parity as the game entered additional time.
Clancy then spurned what looked like being the last scoring chance of the game when he drilled his low shot into the Laois side netting, but from the resulting puck-out Brian Galvin launched a high ball deep into the Clare full-back line and Hyland rose highest to tap past Clare 'keeper Donal Tuohy into the empty net.
Man of the Match: Willie Hyland (Laois)
SCORERS -- Laois: W Hyland 1-10 (7f), J Brophy, N Foyle 1-0 each, J Walsh, S Burke (1f) 0-2 each, J Fitzpatrick, M Whelan (1f) 0-1 each. Clare: N O'Connell 0-7 (4f), C McGrath 1-2 (1f), J Clancy, D Honan 1-0 each, D McMahon 0-2, F Lynch, J Conlon 0-1 each.
Laois -- P Mullaney 6, J A Delaney 7, B Campion 8, B Stapleton 7, J Fitzpatrick 7, M Whelan 7, B Galvin 8, J Walsh 7, S Burke 6, B Dunne 6, G Reddin 7, W Hyland 9, O Holohan 6, N Foyle 7, J Brophy 7. Subs: E Costelloe for Dunne (51), N Costelloe for Burke (64).
Clare -- D Tuohy 6, P Vaughan 7, C Cooney 6, D O'Donovan 8, B Bugler 6, J McInerney 7, P O'Connor 7, N O'Connell 8, S Collins 6, J Conlon 7, F Lynch 6, J Clancy 7, C McGrath 7, D McMahon 7, D Honan 6. Sub: C Morey for Collins (49).
Ref -- M O'Connor (Limerick).