Mevlut Erding's last-minute effort cancelled out Aurelien Chedjou's first-half opener after Rennes had centre-back Onyekachi Apam sent off for picking up two yellow cards in quick succession.
Lille remain third with 46 points from 25 games and trail leaders Montpellier by seven points after the southerners beat Girondins Bordeaux 1-0 on Saturday.
Second-placed Paris Saint-Germain are a point off the pace following a 4-4 draw at Olympique Lyon on Saturday.
Olympique Marseille's hopes of playing in the Champions League next term took a knock when their 16-match unbeaten run in all competitions ended with a 1-0 loss at Stade Brest earlier on Sunday, Paul Baysse scoring after a corner on 17 minutes.
Didier Deschamps's side, who still have a game in hand, dropped to eighth, seven points adrift of Lille who occupy the Champions League play-off spot.
Rennes, who moved up to sixth on 40 points, got off to a good start against champions Lille but Apam was shown two yellow cards in the 36th and 37th minutes for fouling Nolan Roux and Joe Cole.
Belgium midfielder Eden Hazard sent the resulting free-kick dipping into the box for Chedjou to head home as the visitors looked set for a routine win.
Rennes, however, piled on the pressure after the break and came close on several occasions with Lille banking on counter-attacks.
Erding eventually found the back of the net in the 90th minute when he latched onto a Jean Armel Kana-Biyik assist.
Marseille, who had not lost a competitive game in three months, dominated throughout at Brest but home goalkeeper Steve Elana was in superb form.
The visitors were denied a penalty in the first minute when Johan Martial, who later admitted on French TV he committed a foul, brought down Brandao in the box.
Brazilian striker Brandao then directed a header against the post.
Elana made two stunning saves to deny Rod Fanni and Benoit Cheyrou from close range in the second half before tipping an Andre Ayew effort over the bar in injury-time.
Shortly afterwards, Eden Ben Basat cleared a Fanni header off his goal-line.
"We were denied an obvious penalty after 30 seconds of play. It was a big mistake from the referee," Marseille captain Alou Diarra told French TV channel Foot +.
"If we get and score that penalty in the first minute, the game is just not the same."
Toulouse are seventh on 40 points from 25 games after goals by Aymen Abdennour and Emmanuel Riviere gave them a 2-0 win over bottom club Sochaux.
