ENGLISH rider Gary Carter emphatically announced his Hong Kong arrival at Sha Tin yesterday with a 30-1 double that had retaining trainer Derek Cruz beaming with delight. Carter rode a first-day winner but, as so often happens in Hong Kong, had been finding it hard since. One of Britain's brighter young riders, who caused a bit of a stir when he decided to come to Hong Kong, Carter was also delighted with the early birthday present provided by Leprechaun (5-2 favourite) in the opener and gutsy Rocketeer (12-1) in the eighth event on the holiday programme. Carter turns 28 on Wednesday, but the champagne corks were popping last night - and rightly so. The London-born rider displayed icy nerves in the first event to get Leprechaun safely home, but it was all desperately close. On Rocketeer, however, he resolutely held off the challenge of Felix Coetzee on Golden Era (7-1) and was confidently up in the irons as they hit the line. ''It's great. I couldn't be happier about it. Leprechaun is a nice little horse and a real battler, but it was never going to be an open and shut case. ''He is likely to be a bit slowly away and that can pose a problem over the shorter trips. But I wanted to keep him on the fence and angle for a later run. ''I honestly felt it would come and when it did, it was just at the right time. Didn't he take it up well?'' said Carter. As expected, the speedy Turf Champ (7-2) took up the running in the Class Four longer sprint and Leprechaun was shuffled back through the field. But Carter forced the issue at the 300-metre mark and the Irish three-year-old forged through along the rails. It looked for a couple of strides as if there might be nowhere to go, but a tiring Turf Champ rolled away and Carter was through the gap in a flash to go on and score from Diamond Head (30-1), who put in a top run for Eric Legrix. Graceful Win (25-1) had looked really well in the paddock and ran accordingly, eventually fading slightly for third ahead of Turf Champ. Rocketeer produced a surprise victory in the Class Four, 1,200-metre eighth event - at least for Carter. ''Derek (Cruz) was a lot more confident about his chances. He said he was a different racehorse on the track and he certainly gave plenty. You could not have asked for more from him,'' said Carter. ''It's been a really good day for the stable because it does keep us ticking along nicely. It's an important part of the season as Gary and I are just starting out together,'' Cruz said. ''I'm really pleased for Gary. He rode two lovely races and it will be a great boost for him, too,'' he added. There was an excellent run from third-placed Jade (10-1) in Rocketeer's race and it will definitely pay to keep on the right side of bottomweight Stellar Express (10-1). The New Zealand private purchase griffin finished seventh under Frankie F. C. Lor and this is a future winner for the Ivan Allan stable. Troubled Redcap (5-1) finished fourth and Lawrie Fownes may be able to nurse a win out of this fellow.