However, in 1959 he came out of a four-year retirement for one match, to replace Grenchen's injured first choice keeper in the Swiss Cup final against Servette.
His total of 27 appearances for his country make him the third most capped keeper, which is a remarkable achievement considering the lack of fixtures due to World War II.
During his ten-year reign he took the team to their only Schweizer Cup win in 1959, and led them to a final defeat the following year.
With Ballabio at the helm FC Grenchen recorded their best league performances finishing runner-up in 1959 and to third place in 1964.
He remained in charge for World Cup qualification but after a 1–1 draw with Portugal on 2 November 1969 meant they failed to qualify he was sacked.