A confident start from the hosts saw them take the lead at the Parc de Princes through Edinson Cavani's header just before half-time, only for Umtiti to pop up seven minutes from time to rescue a point for the hosts.
It was a spirited performance from the visitors, who should have levelled earlier through Arnold Mvuemba's free-kick, which cannoned off the bar just before the break.
Although the hosts remain unbeaten, a run of three consecutive draws and 10 points from their opening six games means the champions have now made their worst start to a Ligue 1 season since they were taken over by the Qatar Investment Authority.
The result has already prompted a response from club president Nasser Al-Khelaifi, who insisted Blanc's position at the Parc des Princes is safe, although anything less than a win over Caen on Wednesday is likely to lead to further scrutiny and speculation.
In contrast the result is likely to ease pressure on Lyon boss Hubert Fournier, who arrived in the capital having overseen a shock 2-1 win over Monaco last week, ending a run of three straight defeats.
Monaco were again tested on Sunday, as they edged past Guingamp 1-0 at the Stade Louis II, courtesy of a goal from first-half substitute Nabil Dirar.
The Moroccan winger struck seven minutes before the break after replacing the injured Anthony Martial, to seal only a second league win of the season for Leonardo Jardim's side and their first in three league matches.
Saint-Etienne left it late away to Lens, sealing a 1-0 win nine minutes from time through Fabien Lemoine.
A wonderful attacking move saw Renaud Cohade link up with Ricky van Wolfswinkel, allowing Lemoine to carve out enough space for an opportunity and he finished with aplomb.
The reusult was Saint-Etienne's second consecutive win and moves them level on points with early pace-setters Bordeaux and Marseille at the top of the table with 13 points from six games.
Lille missed the chance to go to the top of the league after they were held to a 0-0 draw at home to Montpellier.
Boss Rene Girard will have been disappointed with his side's uninspiring efforts in front of goal, but will be comforted by the fact they remain unbeaten in the league and only one point adrift of top spot in fourth place.
The 60-year-old will be hoping his side can rediscover their scoring touch when they travel to struggling Nice on Wednesday, who have only recorded one win in their last five games.