Paris Saint-Germain's chances of becoming the first side to win six straight Coupe de la Ligue titles were dealt a fatal blow Wednesday at the Parc des Princes.
Marcus Thuram was the hero for Guingamp when he slotted home a penalty in added time to give the Breton minnows a 2-1 quarterfinal victory. It was the third penalty awarded to Guingamp on the day, with Thuram firing an effort well above the bar before Yeni N'Gbakoto's 81st-minute spot-kick leveled the scoreline.
Neymar scored for the hosts in his return from an extended holiday in Brazil, heading home an incisive cross from Thomas Meunier in the 62nd minute to give PSG a 1-0 advantage.
Jocelyn Gourvennec's charges are the first team to top Les Parisiens in a domestic cup competition since Montpellier did so in January 2014 in the last-32 of the Coupe de France. Guingamp were the last side to lift a domestic trophy ahead of PSG's historic run when they defeated Rennes 2-0 in the 2014 Coupe de France final. Guingamp won the 2009 Coupe de France final, also against fellow Bretons Rennes 1-0.
Guingamp now join Monaco, Bordeaux, and Strasbourg in the semifinals. Monaco bounced Rennes from the tournament earlier Wednesday when shot-stopper Loic Badiashile beat counterpart Tomas Koubek in the 11th round of penalties at the Stade Louis II.