He died as a result of an accidental collision with Rangers player Sam English during an Old Firm match at Ibrox.

The following season, he moved to Wellesley Juniors, where his talent was spotted by the local press who predicted that he would become a very good goalkeeper in future.

On 5 February 1927, Celtic beat Brechin City 6–3, but Maley was concerned by the fact his first choice 'keeper, Peter Shevlin, had conceded three soft goals so decided to give 18-year-old Thomson a chance in the next game, which was against Dundee.

The following season, after an Old Firm match where Celtic played against their rivals Rangers at Ibrox Park, Thomson received widespread praise from the press following an "immense" performance.

On 5 February 1930, Thomson was seriously injured in a game against Airdrieonians: he broke his jaw, fractured several ribs, damaged his collar bone, and lost two teeth when making a diving save.

On 11 April 1931, Thomson won the second medal of his career as Celtic beat Motherwell 4–2 in the 1931 Scottish Cup Final.

In his biography of Thomson, author Tom Greig described him as having strong, slender fingers and powerful wrists and forearms.

"[5] In 1931, Thomson got engaged to Margaret Finlay and also started making plans to open a tailor shop in Glasgow.

One Rangers player, also a medical student, said later that as soon as he saw him he gave little chance for his survival, this was also the view of the Celtic team doctor.

Even at the start of the 21st century Thomson's grave in Bowhill, Fife remains a place of pilgrimage for Celtic fans.

Among the great Celts who have passed over, he has an honoured place.Thomson was known for his incredible agility, bravery and safe handling, who produced some magnificent displays of goalkeeping.

Another 20,000 turned out at Glasgow Queen Street station to watch two trains set off with two thousand passengers who could afford to pay the four shillings return fare.

Sam English was cleared of any blame in the incident but he was jeered by Scottish fans afterwards and moved south a year later to play with Liverpool.

In recent years, a book called "My Search For Celtic's John", written by Tom Greig, discusses his personal life and the fatal incident.

Every year children in the Cardenden and Kinglassie districts play for the John Thomson Trophy to help ensure his name is perpetuated.

A play about John Thomson, written by Brian McGeachan and Gerard McDade was performed at Glasgow's King's Theatre from 5 to 10 September 2011.