In trying conditions, they held out despite going scoreless for the final 22 minutes as Grenagh’s late rally came up shy.
Grenagh got off to a great start with Diarmuid Dorgan converting two frees. However Cloyne, who were missing one of their best attackers in the injured Paudie O’Sullivan, came more into the game as his brothers Diarmuid, Eoin and Colm all kicked points to put Cloyne into a 0-3 to 0-2 lead on 20 minutes.
Tadhg Walsh equalised for Grenagh but Cloyne were four points clear at the break, 1-4 to 0-3, thanks to a goal from James Nyhan after he combined with the in-running Colm O’Sullivan two minutes into injury time.
Diarmuid O’Sullivan, who is also coach to the team, got the second-half off to a perfect start when he drilled over a pair of vital frees from very tricky angles.
The former county player was selected at corner-forward but put in a good hour’s work roaming further outfield.
Diarmuid Dorgan bagged his third point following a link up with Paul McCarthy to leave the scoreboard 1-6 to 0-4 after 38 minutes.
Dorgan pointed twice more to cut the margin to three points. But when Grenagh moved Tom Kenny to the edge of the square he was fouled and Gerry Russell converted the free.
Niall Doherty kept the momentum going with a fine point. However, a crucial interception by Brian McCarthy from the kick out gave possession back to Cloyne.
Time ran out for Grenagh who will now meet fellow mid Cork side Canovee in round two.
Scorers for Cloyne: Diarmuid O’Sullivan 0-4fs, J Nyhan 1-0, C O’Sullivan and E O’Sullivan 0-1 each.
Scorers for Grenagh: D Dorgan 0-5 (0-4 frees), T Walsh, G Russell (free) and N Doherty 0-1 each.
CLOYNE: P Considine; J Cotter, Donal O’Sullivan, K Dennehy; G Fleming, B Fleming, B McCarthy; K Cronin, P O’Sullivan; C O’Lomasney, E O’Sullivan, C Smith; Diarmuid O’Sullivan, C O’Sullivan, J Nyhan.
GRENAGH: M Barry; M Lehane, R Dorgan, C Donovan; A Duggan, P McCarthy, K O’Neill; T Kenny, J Russell; D Dorgan, G Russell, N Doherty; T Walsh, L Walsh, S Dorgan.
Subs: C Fitzgerald for S Dorgan (58).
Referee: J Dorgan (Nemo Rangers).