The French team will play holders Toulon or Leinster in the final after Wesley Fofana's second-half try proved the difference as Clermont avenged their 46-6 drubbing by Saracens at the same stage of last year's competition.
The English side scored the opening points through a Charlie Hodgson drop goal but Clermont flyhalf Brock James levelled with a penalty off the post.
Saracens worked tirelessly to deny space to the French side, who produced a brilliant display of attacking rugby to blow Northampton away 37-5 in the quarter-finals.
Hodgson edged Saracens ahead with a long penalty and the visitors led 6-3 at halftime.
Clermont made a fast start to the second half, however, and a delightful chip through by James was pounced on by centre Fofana who dived over the line.
James converted to put the French side 10-6 ahead but Saracens refused to go away and replacement flyhalf Owen Farrell kicked a penalty on his return to action following a knee injury.
Another Saracens infringement at a ruck gave James the chance to extend Clermont's advantage, however, and the ice-cool Australian duly knocked over another penalty.
Toulon play Leinster in Marseille on Sunday.
(Writing by Ed Osmond in London, editing by Mark Meadows)
Share
