Born and raised in French Morocco, Hagelauer moved with his parents to mainland France around the age of 16.

His best performance came at the 1976 Australian Open, where he upset sixth seed Geoff Masters, en route to the third round.

[2] As a coach he spent many years heading the France Davis Cup team and formed a successful association with Yannick Noah.

Under the coaching of Hagelauer, Noah became the first Frenchman in 37 years to win at Roland Garros when he claimed the 1983 French Open title.

Hagelauer's tenure as Davis Cup coach included the drought breaking tournament win in 1991, which was the country's first triumph since 1932.