Review leopardstown 9th Feb Sir Des Champs showed himself to be a leading contender for the Cheltenham blue riband as he got the better of Flemenstar in the Hennessy Gold Cup at Leopardstown.Only fourth in the Lexus last time, the Willie Mullins-trained seven-year-old (11-8) had something to prove and he did so with a smart staying performance against a rival who appeared not to get home.Andrew Lynch held up Flemenstar for most of the way to preserve his stamina, but when push came to shove after the last Peter Casey's stable star could not get to Sir Des Champs, who was driven out by Davy Russell to win by a length and three-quarters.On a great afternoon for Mullins, who sent out four winners, leading RSA Chase fancy Boston Bob put up an amazing performance to win the Dr PJ Moriarty Novice Chase under Paul Townend.The 6-4 favourite looked booked for fourth spot as he appeared to be fading, but with three others jousting for the prize after the final fence he suddenly sprouted wings and cut them down to beat Texas Jack by a nose.Townend was also on board as Champagne Fever (2-1 favourite) bounced back to winning form after his Naas flop when he led all the way to take the Deloitte Novice Hurdle.With market rival Waaheb an early casualty, Champagne Fever had all bar Bright New Dawn beaten at the top of the straight, but he had to be kept going strongly to score by a length and three-quarters.The Dessie Hughes-trained Our Conor (100-30) remains unbeaten over jumps following an impressive show in the Spring Juvenile Hurdle in the hands of Bryan Cooper.Favourite Diakali tried to stretch his rivals from the front, but Our Conor went past him easily on the run to the final flight and cleared away to win by five lengths.Mullins' fourth victory came in the paddypower.com iPhone Fast Bet Handicap Hurdle when Tennis Cap (6-1) led all the way for a Townend treble, while top hunters Salsify (3-1) and Tammys Hill staged a thriller, the former grabbing the prize by a neck.