[3][4] He helped them to promotion to the First Division in the 1905–06 season and made a total of 134 appearances for the club in all competitions, scoring three goals.
[5] Bonthron was a combative player and during the promotion season was at the centre of a serious incident after Manchester United's match at Bradford City.
His treatment of Bradford player Jimmy Conlin during the match enraged the crowd, and after the game Bonthron was attacked by home supporters.
[6] Criminal charges followed against the perpetrators and a Football Association (FA) inquiry resulted in the temporary closure of Bradford City's Valley Parade ground.
[7][6] He joined Sunderland in May 1907, playing 24 games,[8] before moving on the following year to Northampton Town, with whom he won the Southern League championship in the 1908–09 season.