Monaco claim comeback win to retake second spot in Ligue 1
Liam Rosenior's Strasbourg were unbeaten at home this season and went in front just before the half-hour through Ivory Coast international Guela Doue.
It looked as if Monaco might pay the price for a big first-half miss by Breel Embolo when they still trailed inside the final quarter of an hour in Alsace.
However, the principality club won a penalty when a Ben Seghir shot was stopped just in front of the line by the arm of Diego Moreira.
Young Moroccan international Ben Seghir stroked in the spot-kick to equalise in the 79th minute and then converted a Maghnes Akliouche assist to put the visitors ahead with a minute of the 90 remaining.
Stunned Strasbourg conceded again straight from the restart as Saidou Sow was caught in possession, allowing substitute George Ilenikhena to run through and finish.
It was a welcome return to winning ways domestically for Monaco after back-to-back losses, with the result moving them to three points off PSG before the leaders kicked off later at Angers.
Monaco, who have 10 points from a possible 12 after an impressive start in the Champions League, are also three points ahead of Marseille, with Roberto De Zerbi's side suffering a surprise 3-1 loss at home to Auxerre on Friday.
Elsewhere on Saturday, Lens also produced a late fightback as Nigerian midfielder Hamzat Ojediran and Adrien Thomasson both scored in the final five minutes, allowing them to win 3-2 at home to Nantes.
That result lifted Will Still's Lens up to fifth, a point behind northern rivals Lille, who go to Nice on Sunday.