Guingamp have missed the chance to move into sixth place after Benjamin Moukandjo's stoppage-time strike earned Lorient a 2-2 draw.
EAG were ahead inside the opening 60 seconds after Yannis Salibur's menacing cross was turned into the net by Jimmy Briand.
Lorient almost dragged themselves back on level terms when Moukandjo got his head onto Yann Jouffre's delivery, but was denied by Jonas Lossl.
The visitors suffered a setback when Majeed Waris was given a straight red card for his challenge on Briand.
Guingamp were also reduced to 10 men before the interval when Younousse Sankhare was sent off for violent conduct.
Lorient equalised midway through the second period when Moukandjo scored from the penalty spot after the Cameroonian was fouled in the box by Benjamin Angoua.
Despite conceding, Guingamp looked to have to secured victory in the final minutes as Lars Jacobsen crossed for Salibur to net the hosts' second.
However, Moukandjo rose to meet Raphael Guerreiro's corner in the third minute of injury time to earn Lorient a point.
