Irishman Padraig Harrington fired a 10-under par 61, the lowest score of his career, to seize a three-shot lead in the first round of the US PGA Transitions Championship in Florida.
Will Claxton was next best on 7-under 64.
Sunday's World Golf Championship winner at Doral, Justin Rose, shot 4-under 67 as did Luke Donald.
Rory Sabbatini shot a 68, Retief Goosen a 69 and Ernie Els one-under 70.