Horschel came from four shots off the 54 hole pace set by Lucas Glover, his final round of 64 including six consecutive birdies through the middle of his round which gave him the lead.
Those six birdies came after a three hour rain delay and a little later he would again have to wait another half hour after being disrupted again before playing his approach to the 18th hole.
Then it became a case of holding off a late run from D.A.Points. A bogey at the 15th threatened to dampen his hopes of his first PGA Tour victory but a great approach to the 16th followed two holes later by a birdie at the final hole from 35 feet when one ahead of Points sealed the deal.
Horschel has not missed a cut since May of last year and in fact one of the last cuts he did miss was in this very tournament 12 months ago. What a difference twelve months can make as not only is the former Walker Cup star a winner of the event, he has now progressed to number three in the Fed Ex Cup standings, is likely to go close to a place inside the top 50 in the world and has a start at the Hyundai Champion of Champions event and at the Masters.
Horschel played in Australia as a member of the 2008 US Eisenhower side and joined the PGA Tour in early 2010 before an injury caused him to miss most of that year. He returned via a Medical Exemption in 2011 and the rest as they say is now history.
After a very slow start to the season, Points too is in a very good place with his game right now. The four time Buy.Com Tour winners is now a three time winner on the PGA Tour, his runner-up finish coming just three starts after his win at the Shell Houston Open. He dropped just two shots for the week further confirming his good form.
Kyle Stanley finished third two shots behind Points while Lucas Glover was alone in 4th position after a disappointing final day where scoring was made easy by a lift clean and place ruling and calm, albeit, stormy conditions.
The best of the Australians was Matt Jones who has now made nine of eleven cuts this season and although yet to record a top ten in 2013 he is steadily accumulating money.
Rod Pampling was next best in 42nd position.
The PGA Tour now heads to Quail Hollow Charlotte in North Carolina for this week's Wells Fargo Championship.