The 57-year-old chief executive of SmithKline Beecham was ranked tenth in the world at tennis 30 years ago. He played 16 consecutive Wimbledon tournaments and was a regular choice for his native Denmark in the Davis Cup.
Mr Leschly works at business like he played tennis: to win. Outspoken and fiercely competitive, he has been deeply influenced by the US where he now officially lives with his family.
Although educated with a pharmacy degree and MBA from university in Copenhagen, Mr Leschly joined the US-based pharmaceutical group, Squibb Corporation, where he quickly climbed the corporate ladder.
In 1990, Mr Leschly took his American-style openness and keen sense of humour to SB as chairman of the group's worldwide pharmaceutical business. His enormous reserves of energy were used by the then group chief executive, Bob Bauman, to help weld together the still disparate pieces of the recently merged SmithKline and Beecham companies.
Mr Leschly succeeded Mr Bauman in April 1994 and immediately embarked on a whirlwind of activity. In a single year he completed either the sale or purchase of assets worth $10bn (pounds 6.1bn).
Now based in Philadelphia and also on the board of American Express, Mr Leschly has attracted little but praise for his strong corporate leadership. The only real carping has surrounded the size of his pay packet: he earned more than pounds 2m in 1996 which included a pounds 1.2m bonus.
Co-operative in management style, Mr Leschly nevertheless likes to lead from the front. As one colleague remarked: "It probably comes from being the nephew of two Danish generals."