In 1938 he played some promising innings for the Colts team and was called up into the 1st XI for the game with Kent at Maidstone. Ernie was overjoyed to be playing at the first-class level, and was desperate not to make any mistakes, dutifully following the instructions of county captain Maurice Turnbull and the professionals in the county side. When it was Ernie`s turn to bat, the light was getting gloomy, and soon after arriving at the crease, his partner Dai Davies made an abortive appeal against the light. A few overs later, Dai went down the wicket and told young Ernie to ask the umpire Frank Chester about the poor light. Ernie duly spoke to the famous Test umpire, who replied "Tell Dai he hasn`t got a chance, and the shop will be open as usual until 6.30pm!"

Ernie kept his place for the match with Warwickshire at Newport, and the following season he was called up for two games in June against Kent and Somerset. Indeed, it was at Tonbridge in 1939 that Harris hit a career best 25, and had it not been for the Second World War, Ernie might have gone on to better things in county cricket. After the War, he entered the admissions office at University College, Cardiff, thinking that his days of playing first-class cricket were over. But in 1947 Glamorgan were a player short for their game at Sheffield against Yorkshire, and Ernie, who was in good form for St.Fagan`s, was drafted into the team. It was an inauspicious return, as Ernie made 0 and 2, and it ended his county career with a record of 59 runs from 8 innings.

Ernie returned to his job at the university, where he rose to the position of Registrar, and playing for St.Fagan`s. He switched bowling styles to leg spin, and even in his sixties, he still cut a dapper and athletic figure in the field for the club side, and the University Staff XI. He also served on the Glamorgan committee during the 1960`s and 1970`s, and in 1973 Ernie served as Match Manager for the one day international between England and New Zealand at St.Helen`s, Swansea.