Kevin Monnet-Paquet and Romain Hamouma fired St Etienne to within a point of Ligue 1's top four with a stormy 2-0 victory over nine-man Lyon.
Monnet-Paquet's ninth-minute strike got the home side off to a great start at the Stade Geoffroy-Guichard and Hamouma doubled their advantage just 13 minutes later.
In the meantime, Corentin Tolisso had hit the post with a 13th-minute header as the visitors tried to repair the early damage, but Lyon goalkeeper Anthony Lopes had to pull off good saves to prevent Vincent Pajot and substitute Nolan Roux from extending St Etienne's lead.
But in a dramatic conclusion to the game, Lyon had Rachid Ghezzal and Tolisso dismissed and St Etienne's Fabien Lemoine, who had only been introduced as an 88th-minute substitute, also saw red with all three sendings-off coming in stoppage time.
Sergio Conceicao's coaching career at Nantes has taken a turn for the worse after a 2-0 home defeat to Nancy.
The former Portugal winger won six of his first seven games, but has now lost three of the last four.
Winger Issiar Dia and defender Julien Cetout scored Nancy's goals in the second half. Both sides had a player sent off in injury time.
Nancy, who were promoted last season, are up to 11th place, while Nantes are 14th.
Toulouse's winter recruits played a major role in their side's 4-0 win against Angers, a result that ended a four-game losing run for the southwestern club.
The 21-year-old Jean, who joined Toulouse on loan from Monaco until the end of the season, delivered the assist for Delort's opener in the 47th minute, then won a penalty that Martin Braithwaite converted to make it 2-0.
Delort, who signed a 4 1/2 year contract with Toulouse during the January transfer window from Mexican club Tigres, latched on to Jean's cross from the right and slotted home with the help of the crossbar.
Oscar Trejo extended the hosts' lead in the 69th to complete a counter-attack and Ola Toivonen rounded out the rout with a chip over the Angers goalkeeper after beating the offside trap.
PA Sport and The Associated Press contributed to this report.