Zlatan Ibrahimovic's late goal sent Paris Saint-Germain into the Coupe de France final, securing a hard-fought 1-0 win at Lorient on Tuesday.
The holders had struggled to break down a resilient Lorient outfit but the prolific striker came to his side's rescue after 75 minutes with another fine goal.
Ibrahimovic was given space on the edge of the box and his shot was too clever for Lorient goalkeeper Benjamin Lecomte to keep out.
The hosts had chances of their own, with Salvatore Sirigu denying both Abdul Majeed Waris and Benjamin Moukandjo, but PSG held on for their eighth straight victory against Lorient.
PSG's hopes of a historic successive domestic treble are still alive and they extend a club record of 11 successive Coupe de France victories ahead of Saturday's Coupe de la Ligue final against Lille.
Marco Verratti (groin) and Thiago Motta (thigh) missed out for the Ligue 1 champions, while Sylvain Ripoll made four changes to the side that drew 1-1 with Toulouse at the weekend.
After a cagey opening, Maxime Barthelme's excellent cross could not be converted as the hosts, who have not beaten PSG since August 2011, started brightly.
Referee Frank Schneider then had to be replaced by fourth official Sebastien Moreira after suffering an injury.
With 26 minutes on the clock PSG had their first chance, as Edinson Cavani's header was cleared off the line before the striker went close again with a fierce half-volley that was inadvertently blocked by Ibrahimovic.
The Sweden international then went close twice in close succession, first heading a Blaise Matuidi cross just wide and then narrowly clearing the crossbar with a fierce long-range drive.
Waris lashed an effort well over the crossbar shortly after half-time and the striker worked himself another opening after 61 minutes when PSG's defenders backed off, but Sirigu saved the striker's 20-yard shot easily.
Angel Di Maria's 25-yard drive fizzed just wide of the post before Sirigu made another good save, this time from substitute Moukandjo who had broken clear, and that missed opportunity proved crucial as Ibrahimovic then put PSG into the lead.
The striker was given time and space and produced a sublime finish with the outside of his boot to beat Lecomte - his 14th goal in 12 Coupe de France matches.
Lorient had progressed in eight of their last nine home games in the competition but they could not find an equaliser, Sirigu saving Zargo Toure's header in the last minute, with PSG holding on to book their 14th final appearance.