He was an immediate success with his sharp spin, coming second in the Middlesex averages behind Frank Tarrant, whilst in 1910, though erratic, he accomplished a sensational performance against Essex, taking 7 wickets for 2 runs in 25 balls.

In the following years, Hearne's all-round cricket, along with that of Frank Tarrant was a remarkable combination only paralleled by George Herbert Hirst and Wilfred Rhodes at Yorkshire.

Though his opportunities were restricted in 1912, the following two years Hearn accomplished the remarkable feat of scoring 2000 runs and taking 100 wickets in a season, and he went to South Africa in 1913/1914.

After a disappointing season in 1919, Hearne's all-round play won Middlesex the County Championship in 1920, but, like all English spin bowlers of the time, he was remarkably hopeless on the rock-hard Australian wickets and accomplished little even with the bat.

His bowling was affected by injury in 1921, but for the following three years his position as one of the country's premier all-rounders remained intact, with his batting skill on rain-affected wickets having few equals.

However, from 1925 his bowling skill declined, though he was good enough as a batsman for England selection in 1926, and he remained a force to be reckoned with in county cricket into the 1930s – despite a major injury when fielding in 1928.