
The reigning champions were defeated by four points against Rathdowney-Erill.
Clough-Ballacolla began the defence of their Laois Senior Hurling Championhip with defeat last night in Portlaoise.
Rathdowney-Erill ran out with a four point win over the 3-in-a-row winners on a scoreline of 0-21 to 2-11.
A strong final 15 minutes from the 2019 winners, saw them out score their opponents 0-09 to 1-01 with Ross King ending with an impressive 0-14 in a Man of the Match display.
The Harps and Rosenallis will meet in the other Group A fixture on Saturday from O'Moore Park, with throw in at 7:00pm.
Borris In Ossory will face Abbeyleix St Lazarians in Group B tonight in O'Moore Park with a 7:45pm throw in.