Emanuel Steward

Emanuel Steward, who has died aged 68, was a coaching colossus whose boxers straddled the 20th and early 21st centuries.

He may have spurned the 1964 Tokyo Olympic boxing trials to complete his apprenticeship as an electrician, but the man whose love of the sport began when his parents gave him a pair of boxing gloves for Christmas in 1952 found his true calling when he became the Kronk Centre boxing team coach in Detroit for $35 per week.

Twenty years later, he turned down a promotion and $500 a week from the electrical company he was working for in Detroit to work as a full-time boxing coach at the Kronk gym. It was there he discovered the boxer Steward claimed was the greatest potential champion he trained but never was: Bernard Mays. To his eternal chagrin, he lost him to drink and dope addiction.

He also discovered a tall, gangly, youth called Thomas Hearns – the future Motor City Cobra or Detroit Hitman – who Steward turned into a boxing world welterweight champion in 1980. He also took lightweight Hilmer Kenty to world champion status. Hearns and Kenty were the first of a galaxy of world champions who benefited from Steward's ability to read opponents' styles and weaknesses.

He attributed his catalogue of success to his belief he should control every aspect of his fighters' training camp and regime.

So strongly did Steward believe this personal credo of total boxer control that he attributed Thomas "The Hitman" Hearns's two major career losses to him not having his usual total control of his boxers training camps. Critics might have dismissed this as control freakery but the procession of world champions who were guided by Steward were his best answer to critics.

World champions such as heavyweight Lennox Lewis, Dennis Andries and Milton McCrory were a few who benefited from Steward's skill.

Britain's first 20th-century world heavyweight champion Lewis had unhappy experiences with trainers until he hooked up with Steward. He turned his admiration for Lewis into hard, outstanding achievements such as Lewis defeating Evander Holyfield and Mike Tyson.

Steward never regarded his charges as cash cows.

For example, on the eve of one of the 20th century's world title clashes – the epic Las Vegas April 1985 clash between middleweight champion Marvin Hagler and Tommy Hearns – Steward told Hearns that with accumulated career earnings of $30 million, including $11m for his fight with Hagler, Hearns should quit the ring regardless of the result and enjoy his wealth rather then hang around too long and suffer the risk of post-fight physical impairment. This was typical of Steward's philosophy.

Steward is survived by his wife Marie and their two daughters.