As a member of the Munster inter-provincial team on a number of occasions, Ahern won one Railway Cup medal.
It was the beginning of a great era of success for the club as further final victories over Glen Rovers in 1930 and Éire Óg in 1931 brought Ahern's championship medal tally to seven.
Ahern made his senior championship debut for Cork on 24 August 1919 as Limerick were the opponents in what was the provincial decider.
A 3–5 to 1–6 victory gave Cork the title for the first time in sixteen years, while Ahern collected his first Munster medal.
Cork, who were wearing the distinctive red jersey for the very first time, proved too good for the metropolitans and had a commanding 4–2 to 1–1 lead at the interval courtesy of four goals by Jimmy "Major" Kennedy.
Dublin could not stop the Cork onslaught as "the Rebels" went on to secure a 6–4 to 2–4 victory and a first All-Ireland medal for Ahern.
Joe Phelan went on the rampage and scored four goals in quick succession to give Dublin a merited 4–9 to 4–3 victory.
Cork went into a period of decline over the next few years, however, the team bounced back during the 1925–26 league, the inaugural running of the competition.
Cork retained the provincial crown in 1927, with Ahern collecting a fourth Munster medal following a 5–3 to 3–4 defeat of Clare.
Cork fought back in the third quarter, however, an expert display of goalkeeping by Tommy Daly saved the day by keeping Ahern scoreless, as Dublin went on to win by 4–8 to 1–3.
Ahern's brother, Mick, ran riot scoring 5–4, a record for an All-Ireland final, as Cork triumphed by 6–12 to 1–0.
Ahern won a sixth Munster medal in 1929 as Cork made it four-in-a-row following a 4–6 to 2–3 defeat of Waterford.
Cork exited the championship at the first hurdle in 1930, however, Ahern finished the year by winning a second league medal following a 3–5 to 3–0 defeat of Dublin the decider.
The first half was closely contested, with a goal from Mick Ahern helping Cork to a half-time lead of 1–3 to 0–2.
Kilkenny's Lory Meagher was playing the best hurling of his career at this time and scored a magnificent point from 90 yards out the field.
In spite of this great effort a winner couldn't be found and both sides finished level again at 2–5 apiece.
It was also suggested at a meeting of Central Council that both teams be declared joint champions and that half an All-Ireland medal by given to each player.
As the All-Ireland saga went to a third meeting on 1 November 1931, Kilkenny's captain Meagher was ruled out of the game because of broken ribs sustained in the first replay.
Such was the esteem in which he was held the game was virtually conceded to Cork since the star player couldn't play.