At Stockholm, Kelly won his preliminary heats easily and qualified to the final with four more Americans and one representative from Great Britain. From the start, the five Americans ran even until the eighth hurdle, where Kelly and James Wendell spun ahead to decide the winner. Kelly got in front the instant before the tape was broken to win by 0.1 seconds. He also competed for the USA in an exhibition baseball tournament in Stockholm.
Kelly was the AAU Champion in 120 yd (110 m) hurdles in 1913 and finished second in 1916 and 1919. Kelly also finished first at the 1915 AAU Championships but was disqualified for knocking down four hurdles.