Yusuf Yazici scored what proved to be the winner as Lille beat fellow title hopefuls Monaco 2-1 on Sunday to retake second place in Ligue 1, while Lyon cruised past Metz as the pair increased the pressure on leaders Paris Saint-Germain.
Christophe Galtier's men dug deep at the Stade Pierre-Mauroy to end Monaco's four-match winning streak and move back to within two points of reigning champions PSG.
Lille, who were held to a draw by struggling Saint-Etienne last weekend, had the best chance of the opening half but Jonathan Bamba's strike was well saved by away goalkeeper Vito Mannone.
Lille broke the deadlock in the 53rd minute. Jonathan Ikone avoided two challenges on the edge of the area before slipping a pass through for Canadian striker Jonathan David to score.
The hosts doubled their advantage midway through the second half as Turkish internationals Burak Yilmaz and Yazici combined, with the latter slotting in from close range.
Yazici, who was introduced as a substitute three minutes before his goal, has scored four times in the league this season despite only starting twice.
Pietro Pellegri pulled one back for Monaco in the 90th minute, but there was not enough time for an equaliser.
The principality club sit fifth, five points behind PSG, who saw off Montpellier 3-1 on Saturday.
"It would have deserved to end in a draw, so I am inevitably disappointed," said Monaco boss Niko Kovac.