INDONESIAN world number one Heryanto Arbi and Bang Soo-hyun of South Korea retained their singles crowns in the Nin Jiom Hong Kong Open Championships at the Queen Elizabeth Stadium yesterday. Both top seeds overcame first game losses to go into the record book as the first men's and women's champions to successfully defend their titles together in the 11-year history of the event. Arbi, playing his first tournament since pulling a thigh muscle at the Indonesian Open three months ago, wore an elastic supporter on his right thigh as a precautionary measure. He was a bit tentative in the opening set but his superior fitness proved decisive as he defeated compatriot Allan Budi Kusuma 13-18, 15-13, 15-4. Kusuma led early until Arbi won five points on the trot to surge ahead 13-10, but the 1992 Olympic champion clawed back to 13-13 and reeled up five straight points for the opening set. Kusuma again took the early lead in the second set before Arbi raised his game to win four points for a 14-12 advantage. The second seed rallied to save two set points and closed the deficit to 13-14, but Arbi made no mistake this time and sealed it with a powerful jump smash. An exhausted Kusuma hardly put up any resistance in the final set as world champion Arbi breezed through the decider for his fifth Grand Prix title of the year. South Korea's Bang recovered from a lackadaisical start to beat Indonesian teenage sensation Mia Audina 5-11, 11-4, 11-5 to retain the women's crown, her third Hong Kong title in four years.