The Australian coach of French rugby club Racing Metro, Simon Mannix, has been left fuming after his team's 21-17 Top 14 finals defeat on Friday.

Mannix claimed touch judges had called one of Morgan Parra's second-half penalty attempts for Clermont good despite the ball appearing to drift high and wide of one post.

"Clermont are a great team and they don't need that to win a match," Mannix said.

"It's disgusting."

Parra's left boot and a late yellow card for Racing lock Santiago Dellape were the decisive factors in the match, which ensured Clermont a spot in the Top 14 semi-finals.

Clermont five-eighth Brock James had earlier missed two penalties, having scored from two previous events, so Parra took over the kicking duties and proved up to the task with a faultless display.

"That was complicated because we didn't wrap it up in the first-half when we failed to turn our domination into points," said Clermont flanker Julien Bonnaire.

"And then the only time they came into our territory, they scored.

"The solidarity of the team paid off tonight."

In a mistake-ridden first-half, Racing failed to win much of their own line-out ball in a game dominated by forward confrontations and a raft of basic handling errors.

Against the run of play, South African flanker Jacque Cronje forced his way past Julien Malzieu and Aurelien Rougerie for a try in the corner that Jonathan Wizniewski failed to convert to leave the score at 6-5 to the home side at the break.

Wizniewski knocked over a penalty early in the second half with team-mate and Springbok Francois Steyn kicking a long-range effort shortly after.

In-form France halfback Parra clawed back three points with his own 50-metre penalty but Clermont were struggling at the set-piece and after a series of strength-sapping scrums, Wizniewski kicked an easy drop-goal.

Parra scored a second penalty after Steyn was penalised for failing to roll away in the tackle to peg back the score to 12-14 with 20 minutes to play.

The 23-year-old South African turned from villain to hero almost immediately, fielding a ball on his own 10m line and striking a 60-metre drop-goal sweetly through the posts.

Italian Dellape was then yellow carded for taking out Parra with a swinging arm, with the No.9 subsequently nailing his third penalty, although it left Racing coaches furious as they thought it had not gone through the uprights.

Clermont destroyed the visitors at one subsequent scrum, Fijian winger Sireli Bobo deputising for Dellape, and Parra kept up his impeccable evening with the boot with a fourth penalty seeing the home side once again take the lead with 10 minutes remaining.

Former All Black Andrew Mehrtens failed with a late drop-goal attempt for Racing, and when Steyn was penalised for a high tackle on Rougerie, Parra made no mistake with his fifth shot at goal to ensure a semi-final game against Toulon at St Etienne on May 15.

The other play-off sees Toulouse hosting Castres on Saturday for the right to a semi-final berth against Perpignan, which will be played at Montpellier on May 14.

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