SIOUX FALLS, S.D. (AP) – A man who appeared to win the Sioux Falls Marathon was disqualified for running the wrong course, but he said he was not trying to cheat.

Olok Nykew, 37, of St. Paul, Minn., registered for the full marathon and crossed the finish line first Sunday. But his fast time raised eyebrows, and race officials determined that he had run only the half-marathon.

The two races followed separate but sometimes overlapping routes through South Dakota’s largest city before ending at the same finish line. Nykew and other runners of the full marathon wore black identification numbers, while half-marathoners wore red numbers. The marathon began at 6:45 a.m. and the half-marathon at 7:30.

“He registered for the marathon and ended up running the half and came in 25 minutes faster than the record. They figured it out and disqualified him,” Jason Richards, project director for the Sioux Falls Sports Authority and assistant race director for the marathon, told the Argus Leader newspaper.

“I don’t see how he could have gotten lost,” Richards said.

Nykew said he thought the full marathon began at 7:30, the start time of the half-marathon, and that he knew something was wrong when he got to the finish line.

“I thought, what is this?” said Nykew, who moved to the U.S. from the Sudan in 1998. “When I got there, I thought it was not long enough. I’m thinking I’m not cheating. I was just confused. It was an honest mistake.”

There was never any question whether Nykew was the legitimate winner of the marathon. Officials monitoring the marathon route stayed ahead of two men who were leading the pack almost stride for stride in an even race, and the news that another runner already had finished indicated something was wrong.

The winner was Justin Gillette, 29, of Goshen, Ind., with a time of two hours, 30 minutes and 10 seconds. Kelly Brinkman, 31, of Bloomington, Minn., was the top women’s finisher at 2:50:38. Both times set race records.

More than 2,200 runners took part in the marathon, half-marathon and 5-kilometer run.

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