Title-chasing Cork City produced a workmanlike display to see off ten-man Derry City.
Cork went close to taking an early lead but Derry goalkeeper Gerard Doherty did well to deny Karl Sheppard, turning his effort around the post.
Derry went close on 17 minutes when Dean Jarvis' left wing centre found Philip Lowry, but the midfielder's header at the near post bounced before Mark McNulty gathered.
Cork missed a golden chance on 50 minutes when Darren Dennehy's header into the six-yard box was somehow missed by duo Sheppard and Mark O'Sullivan.
Sheppard made up for that miss as he did find the back of the net on 58 minutes - impressively firing home past Doherty, from the right-hand side of the Derry penalty box.
The visitors rightfully added a second on 88 minutes from the penalty spot after O'Flynn was bundled to the ground by Aaron Barry.
To make matters worse for Derry, the defender was sent off for the challenge and Billy Dennehy blasted home the spot-kick.
Derry City - Doherty, Kelly, S McEleney, Barry, Jarvis; Curtis (Dooley 73), McNamee, Lowry, Timlin; P McEleney; Curran.
Cork City - McNulty, Gaynor, Bennett, D Dennehy, K O'Connor; Murray, Miller, Buckley; Sheppard (Lehane 90), O'Sullivan (O'Flynn 58), B Dennehy (Kearney 90).
Ref - P Sutton (Clare)