Following his victory in the mountain race GP Peugeot, Monseré was included in the Belgian national team for the 1968 Summer Olympics as a support rider for Roger De Vlaeminck.

He became professional for Flandria in 1969, and won the Giro di Lombardia that year, after Gerben Karstens tested positive for taking amphetamines.

Monseré continued to affirm his exceptional qualities, including his self-discipline and hunger for victory.

He owed a lot to the strong bond with his blind masseur Jacques Delva, who, among other things, let him perform the basic yoga asanas.

In the final, Eddy Merckx encouraged Monseré to chase the leading cyclists, saying 'if you want to win, you have to go to Gimondi'.

On 15 March 1971, Monseré was riding the Grote Jaarmarktprijs in Retie after being convinced by Eric and Roger De Vlaeminck to participate.

On the road from Lille to Gierle, he and Roger De Vlaeminck agreed they had trained enough and they were about to exit the race.

[8] In a cruel twist of fate, in 1976 Monseré's seven-year-old son Giovanni died after a collision with a car, while riding his racing bike which was given to him on his first communion by a family friend, another world champion Freddy Maertens.

[9] Investigation of the accident showed blunders of both the local law enforcement forces and the race organization.

As it was a small local race, the gendarmerie had refused to cooperate, and the police did not find it necessary to stop traffic on the course.