Nad Al Sheba hosts its first stakes race of the season Thursday when Round 1 of the Maktoum Challenge, a Group 3, $200,000 race at a mile on dirt, heads a seven-race, $830,000 card that starts the Dubai Racing Carnival.\nLast year's winner, Happy Boy, is one of four horses who will be saddled by Mike de Kock, the South African trainer who has a powerful stable in Dubai this year. But Happy Boy has been unplaced in four outings since then, including a dull seventh in a modest Great Leighs allowance last time on Sept. 27. His stablemate Royal Vintage, second in the UAE Derby, was fourth in that Great Leighs race and rates a favorite's chance with Kevin Shea at the controls. A third de Kock inmate, Art of War, is eligible to improve off just three lifetime starts in his native South Africa, where he was a one-mile handicap winner on turf.\nThe Pascal Bary-trained Brazilian-bred Gloria de Campeao rarely fails to run well. Second in this race last year, she was also second to Jalil in Round 2 of the Maktoum Challenge at 1 1/8 miles before finishing sixth in the Dubai World Cup. Christophe Lemaire is in from France for the ride.\nSaeed bin Suroor will give Frankie Dettori a leg up on the Godolphin-owned My Indy. Bred in Argentina by Haras La Quebrada, My Indy was sixth behind Honour Devil and Royal Vintage in last year's UAE Derby and third behind the same two in the UAE 2000 Guineas. A Group 2 winner in Buenos Aires, he may prove the biggest threat to Royal Vintage.