With its first win since Oct. 5, Nantes came within a point of the league’s top three.
Last-place Toulouse had its fifth consecutive loss.
During a scrappy first half of few chances, a turning point came in the 24th minute when midfielder Kouadio Kone was sent off for a second yellow card.
Nantes tried to take advantage of the space left by Toulouse’s defense but missed three consecutive chances near the half-hour mark before referee Florent Batta awarded the hosts a penalty following a handball in the box.
Toure converted from the spot before Blas, who was influential throughout, sealed Nantes’ win with a powerful strike under the bar for his second goal this season.
Aaron Leya Iseka pulled one back deep in stoppage time.