ocr: O'Brien Stakes Claim To - Decathlon Record Byl MICHAELJALJANOFSKY THB NEW YORK TIMES, 1991 TOKYO, Aug. 30 - 1f it was Dan O'Brien's misiortune to: set an Ameri- can record in the decathlon on the night that Mike Powell broke the world record in the 'long jump, the circumstances were lost on O'Brien. "This is fantastic, - he said tonight after his total of 8,812 points won the gold medal at the world track and field champlonships and replaced Bruce Jenners 8,634 at the 1976 Olymplcs in Montreal as the highest total by an American. "I was hoping for a world record, O'Brien continued. "But some t ...