However it was under Fogarty's successor, Dave Bacuzzi, that he became a prominent member of the successful Hibs team of the early 1970s.
Dennehy helped Hibs win several trophies including the League of Ireland title in 1971, scoring twice in the play-off decider against Shamrock Rovers.
Under manager Dave Mackay he established himself as a first team regular but lost his place under Brian Clough.
After just one season with Rovers he signed for Cardiff City but never made any first team appearances and was released from his contract in January 1979.
Throughout his time in England, Dennehy regularly played Gaelic football and in 1976 he won a championship medal with Warwickshire.
On 3 July 1973, at Lansdowne Road, Dennehy also came on as a late substitute for a Shamrock Rovers XI in a 4–3 defeat against Brazil.
The Rovers XI was actually an All-Ireland XI which featured both Republic of Ireland and Northern Ireland internationals [3][5] Dennehy eventually returned to Cork where he coached junior soccer teams and played hurling for St Vincent's GAA (Cork).