Douglas Whyte and John Size may have been in conservative mode after Clean Sweep won his second Class Four race at Sha Tin three weeks ago, but both acknowledged the progressive four-year-old after he completed a hat-trick in yesterday's final event in the higher grade. Clean Sweep overcame a wide passage from barrier 14 and was deep without cover for most of the trip. But just when he might have given his rivals a glimmer of hope, the gelding unleashed his hidden reserves and ultimately won the race by a comfortable 11/2 lengths from Ample Gains (Olivier Doleuze). 'You'd have to say there was a lot more merit in that win,' Size said. 'In his previous wins he's been smothered away and getting all the breaks of the race, and had slightly softer ground in his favour as well. 'Today, he was out there, racing forward, exposed all the way and racing on a much firmer track. And yet he's still won convincingly. You'd have to say that was his best win to date.' The 'Dream Team' of the prolific premiership-winning trainer and jockey has been giving backers a consistent return this season. Clean Sweep was their eighth win for the new term, from only 28 runners - a strike rate of 28.6 per cent. The race kept Size in front in his bid to regain the trainers' premiership, which he has won in three of the four years he has been in Hong Kong. He now leads fellow Australian John Moore on a 10-9 scoreline. Clean Sweep also completed a double for the Durban Demon, with Whyte having earlier won on emerging stayer Syllabus, trained by David Ferraris for former Jockey Club chairman Sir John Swaine. 'The horse is thriving under David's training and is just improving all the time. I can't wait to ride him in a race over more ground. He's now won four in a row but he's not finished yet,' said Whyte.