Billeted in Northampton during the war years, Thomas had attracted the attention of groundsman Alf Stockwin when he came to bowl in the nets at Wantage Road.
His debut, against the Australian Imperial Forces side in 1919, was not a great success, but Northampton Grammar School took him on as groundsman and coach, giving Northamptonshire the opportunity to keep tabs on him.
They decided to take another look and he justified their interest with 9–30 against Yorkshire at Bradford in 1920 with the last seven wickets only costing him six runs, and one lifting ball hit wicketkeeper Walter Buswell in the eye and put him out of the match.
That same season saw him earn a £2 bonus from the Mayor of Northampton after he and Vallance Jupp skittled Bill Woodfull's Australians, including Donald Bradman, for 93 and made them follow on.
An elbow injury, which necessitated surgery, ended his county career in 1933, he was granted a testimonial which didn't amount to much, and turned to the Birmingham League where he sent down many more maidens for Kidderminster, Aston Unity and Old Hill before putting away his boots in 1948.