Rennes ride luck to go second
Montano scored from the spot with two minutes left to win a game Rennes led at half-time through Yann M'Vila before an own goal from Kevin Theophile-Catherine levelled matters just after the hour mark.
Rennes are now two points behind league leaders Lille, who suffered a 1-0 defeat at Montpellier earlier today, but they needed luck on their side as Toulouse three times hit the frame of the goal.
Rennes began the game on the backfoot, with Toulouse rattling the crossbar 13 minutes in when Franck Tabanou was unlucky to see his shot rebound off the woodwork.
The hosts continued to attack, with Nicolas Douchez required to make a fine save to deny Paulo Machado before punching clear another effort from the same man moments later.
Rennes' first attack of note did not come until the 39th minute when Montano sought to capitalise on a mistake from Daniel Congre, only for Marc Vidal to make a fine save.
They got the goal in first-half stoppage time when Vidal got a hand to but could not keep out M'Vila's free-kick.
Rennes should have been two goals up early in the second half when Vidal could only push Abdoul Camara's powerful effort into the path of Alexander Tettey, but he missed the target with the goal gaping.
And they paid the price as Theophile-Catherine turned the ball into his own net under pressure as he tried to deal with Romain Danze's cross.
Moussa Sissoko could have put Toulouse ahead in the 69th minute but his left-footed shot came back off the post, while moments later Federico Santander hit the woodwork again as the hosts' frustration grew.
Rennes then escaped with all three points when Vidal brought down Jerome Leroy in the area and Montano sent his penalty straight down the middle.