Perth - Cameron Shepherd scored a try in each half to keep alive the Western Force's slim hopes of a semi-final place after they beat the Lions 55-14 in their Super 14 match at Subiaco Oval on Friday.Shepherd also had a possible third try disallowed by television referee George Ayoub, who adjudged the winger to have a foot in touch before dotting down despite the replays showing both his feet in the air and his body within the field of play.The Force (28 points) were also awarded two penalty tries in the match to help them move to fifth place on the table, leapfrogging the Blues (28), who play the Reds on Saturday, and the Waratahs (28), who have a bye this week.Drew Mitchell, Matt Giteau, James O'Connor and replacement prop AJ Whalley all also scored tries for the Force, who surpassed 50 points for the first time in Super rugby.Giteau slotted six conversions and added a penalty for a personal tally of 20 points."The boys did exceptionally well tonight. It was a bit greasy but we played with some real flair," Force captain Nathan Sharpe said in a televised interview. "I don't know how many tries we scored but we could have scored some more."Referee Paul Marks awarded a penalty try in each half, the first when Ernst Joubert tackled Scott Staniforth without the ball after the winger had kicked through with the line open and no Lions players covering. Joubert was sinbinned for the offence.The second penalty try came when Giteau charged down a clearing kick behind the tryline and Ayoub believed a try would have been scored by O'Connor had he not been held back by US international Todd Clever as he chased the loose ball.Jannie Boshoff and Earl Rose scored tries for the Lions, while Andre Pretorius converted both."Defensively we were very poor in the one on one tackles," said Joubert. "We didn't really have any ball in hand and the ball we did have, we chucked away."