Paris Saint-Germain clinched a record 11th French league title after drawing 1-1 at Strasbourg on Saturday to move four points of second-place Lens with one game left.
It was Messi's 496th career league goal in Europe, breaking Cristiano Ronaldo's scoring record for Europe's top five leagues.
Lens secured second place and automatic entry into next season's Champions League by beating relegated Ajaccio 3-0 at home.
Defending champion PSG overtook former French powerhouse Saint-Etienne, which won its 10th title in 1981 but was relegated to the second division last season.
PSG has won nine of its 11 titles since Qatari backers QSI took charge 12 years ago, with the first of those in 2013. PSG's other titles were in 1986 and '94.