After two solid years he moved to the Pro League with RFC Liège, appearing in European competition with the club and also being instrumental as it won its first-ever domestic cup, in 1990.
On 8 December 1993, he scored with his (weak) right foot to take a 3–0 lead at Werder Bremen in the UEFA Champions League group stage, but the German club made an unlikely recovery to take the match 5–3.
[1] Boffin moved abroad aged 32 as he signed with FC Metz, where he was dubbed La mobylette due to his speed.
In his debut campaign, which started on 2 August 1997 with a 1–0 win at Olympique Lyonnais, he helped to a best-ever finish in Ligue 1, a second place; in spite of his age, he continued to feature regularly for the French side.
[2] In January 2001, Boffin returned to his first club, helping it always maintain its top flight status while the player posted the best scoring records of his career, with 11 and 12 goals in two separate seasons.