Henley wins Honda in playoff as McIlroy struggles
Russell Henley celebrates with the trophy after winning The Honda Classic at PGA National Resort and Spa on March 2, 2014 in Palm Beach Gardens, Florida - by Sam Greenwood
Henley rolled in his birdie putt at the par-five 18th for the victory after Northern Ireland's two-time major champion McIlroy, Scotland's Russell Knox and American Ryan Palmer had all parred the par-five that served as the decider.
Henley had parred his final three holes after a double bogey at the par-three 15th to close out a two-over par 72 and finish the tournament on eight-under 272.
McIlroy, who held the outright lead at the end of each of the first three rounds, endured a difficult day at PGA National, posting a four-over 74, while Knox carded a one-over 71 and Palmer posted a one-under 69 to join the leading group.
Despite his struggles, McIlroy had a chance to win at the final hole of regulation, where he stuck his 240-yard second shot 11 feet from the pin, but he couldn't convert the eagle putt.
Billy Hurley carded a 68 to finish fifth on 273. Canada's David Hearn with a 67 and Will MacKenzie with a 70 shared sixth on 274.
World number one Tiger Woods withdrew after 13 holes citing back pain.
Woods, who had barely made the cut but came alive with a five-under 65 on Saturday, was five over for the day when he called it quits.
The player said he didn't yet know if he would be fit enough to defend his title at the World Golf Championships Cadillac Championship at Doral starting Thursday.