He famously made the fourth round of the 1976 French Open, despite entering the draw as a last minute lucky loser.

[2] After losing in the final stage of the qualifiers, he had given up getting an opportunity to play in the tournament so spent the second day of the opening round touring Paris and visiting the cinema.

He then beat José Edison Mandarino in a second round match which went to five sets and next faced Juan Gisbert, who had earlier accounted for 12th seed John Newcombe.

During the tournament, France was experiencing a heat wave and Mignot coped better with the conditions, as in both of his matches which went the distance he won the fifth set 6–0.

In Davis Cup competition for Belgium he had wins over Željko Franulović and Tom Okker.