In 2017, he finished top of the DPA Australian Pro Tour ranking table, and made his PDC World Championship debut in the 2018 event.
In 2018, Mathers continued playing in Australia on the DPA circuit, winning a tournament in Hobart and making it to the final on two other occasions.
He returned to Australia and at the end of the season he topped the DPA Pro Tour, which secured him a spot in the 2021 PDC World Darts Championship.
He served as a second reserve player for the World Championship and after the withdrawals of Charles Losper (replaced by Mike De Decker) and Juan Rodriguez, Mathers entered the tournament as the second highest ranked runner-up from the PDPA Qualifier.
He saw off New Zealand's Mark Cleaver in the quarter-finals and then overcame emerging youngster Jaymie Hilton-Jones in the semifinals, after what he met Harley Kemp in final.