Lucas Moura and Adrien Rabiot put the visitors 2-0 in front inside 20 minutes, but they proceeded to let in four goals in a most incredible collapseParis Saint-Germain surrendered a two-goal lead as it slumped to a shock 4-2 defeat away at Bastia on Saturday afternoon.
Lucas Moura and Adrien Rabiot put the Ligue 1 champions two goals in front, but incredibly they proceeded to throw away their advantage.
Ryad Boudebouz pulled a goal back on 32 minutes before Francois Modesto and a Julien Palmieri double completed the most dramatic of comebacks.
PSG looked threatening from the kickoff and was rewarded inside the opening 10 minutes as Lucas broke the deadlock with a composed finish.
Yohan Cabaye played a superb long pass over the top of Bastia's defense and Lucas held off the challenge of Florian Marange before lifting the ball over the onrushing Alphonse Areola.
Lucas should have doubled his tally three minutes later having been released by Zlatan Ibrahimovic, but he dragged his shot wide of Areola's goal.
PSG did not have to wait long for a second goal, though, as Rabiot netted in the 20th minute.
The midfielder was the beneficiary of some assiduous work from Blaise Matuidi and Maxwell, who combined to steal possession and set up Rabiot to fire home first-time from 12 yards.
Despite its dominance PSG then gifted the hosts a way back into the game. Van der Wiel handled a right-wing cross, with Boudebouz coolly slotting the spot kick past Douchez.
And, on the brink of halftime, Bastia was level as three PSG defenders failed to clear a corner, allowing Modesto a free header from close range.
No doubt frustrated at throwing the lead away, PSG came out in full attack mode in the second half, with Ibrahimovic the first to test Areola from a 20-yard free kick.
However, a stunning volley from Palmieri gave the hosts the lead four minutes before the hour, the 28-year-old firing into the top corner after PSG poorly cleared a left-wing corner.
Blanc's side pushed for a leveler, but it was Bastia which got the final goal as Palmieri met Abdoulaye Keita's cross to volley past Douchez and give the Corsicans a memorable victory.