HAPPY Birthday can start punters off on a winning note in the opening event at Sha Tin this afternoon. It may only be a Class Six event, but so often the best bets are to be found in this bottom grade simply because they can be reduced to just a few chances. That is exactly the case with today's race for which the booking of triple champion jockey Basil Marcus looks to be highly significant for Happy Birthday. Just for the record, Marcus celebrated his birthday on Thursday. Last time out the Lam Hung-fie trained gelding found the equitrack surface all against him, as was the minimum sprint trip of 1,030 metres. But he has worked in exceptional fashion since then on a good few occasions, notably in a trial down the straight 1,000-metre chute and then on Thursday morning when Marcus bounced him out of the barriers. There was a real zest and fluency to Happy Birthday's work and he appears to have thrived since moving to Lam at the start of the season. His improvement has not been lost on Marcus who is a past master at jumping on horses which are poised to hit form. The fact that he is doing so for his former guv'nor, the very man who brought him to the territory in the first place back in 1990, looks to be doubly pertinent. When Marcus rides for Lam these days it is because they mean business. Happy Birthday should also be at reasonable odds as he does not come into this 1,200-metre race with exactly exposed form, especially after that seemingly so-so performance on the equitrack surface. The biggest danger could well come from Gary Ng Ting-keung's Po On King who is a very consistent performer in this grade. He ran creditably over a mile in a better race than this on the equitrack last time out and will be suited by the longer straight. He had no luck in running last time he encountered a Class Six field when repeatedly baulked in the home straight. Today's Special must also be respected after some consistent efforts against similar company. His stablemate, Shyana, drops into Class Six for the first time which is worth noting. The booking of Gerald Mosse also leaps out of the page as he only ever rides for Wong Tang-ping when the stable expect a bold showing. This is another reason that Happy Birthday should start at good odds as Mosse, riding out of his skin yet again, is likely to be all the rage with the betting public. Shyana is only small and he may struggle to shoulder the 135 pounds. David Hill and John Marshall appear to have an outstanding chance with Top-Worth in the featured Hong Kong Club Challenge Cup. Top-Worth sauntered home in the most impressive fashion imaginable on his only griffin start of last season and is a lovely looking individual. However, he was disappointing first time out this season when a somewhat plodding sixth to Star Of Marble over today's course and distance of 1,400 metres back in mid October. In hindsight, he probably needed the run and it is amazing how that one run can bring a horse on so much. Recent examples of this include the wins of Charity Supporters and Champion Mascot on Wednesday night. Both disappointed on their previous starts which served to bring them on considerably. Top-Worth has certainly been trialing and working in the most exuberant fashion. He impressed when scoring down the straight in a trial on December 20 and since then he has left the likes of Time Fit and Think Tank toiling in his wake in a couple of very serious hitouts. He is definitely worth another chance to confirm the promise of last season. The main quinella threat may come from Green Supreme who has also impressed in his work and now has Mosse on board. Green Supreme stayed on really well behind Got It Made to snatch the quinella spot over 1,200 metres on International Cup day, is fitter and should relish the move to 1,400 metres. Patrick Biancone's Big Mac has been unlucky to run up against such improving youngsters as Top Performance and Flying High on his last two starts and is another likely to be forcing Top-Worth all the way to the line. Zeus is at the top of his form and must be respected as must Able Monarch who seems to appreciate having Walter Swinburn on his back. That is how it has looked during trackwork. English riding star Alan Munro can open his account with Peace Gallery in the eighth event. Peace Gallery had no luck last time and is approaching his peak.