GREENSBORO, North Carolina, Aug 20, 2012 (AFP) - Garcia, one of 38 players returning to the course Monday to complete a final round halted by rain, carded a 66 for an 18-under par total of 262.
It was Garcia's first US title since he won the 2008 Players Championship, and his first title worldwide since his back-to-back victories on the European Tour last October.
"Obviously I won a couple of times last year in Europe, but it's been a while here (in the United States) and it feels great," he said.
Garcia started the week at 11th on the World Points List, with the top 10 on the list earning automatic berths on the European Ryder Cup team to take on the United States in September.
The points for the victory took him to fifth, and with just one more eligible event remaining at Gleneagles he can't be pushed out of the top 10.
European captain Jose Maria Olazabal will also make two captain's picks for the team for the biennial match-play showdown.
Garcia led after the third round and was atop the leaderboard when fourth-round play was suspended Sunday because of heavy rain.
After a bogey dropped him into a tie for the lead the Spaniard birdied four holes in a five-hole stretch to regain the advantage.
Garcia began his march to the title with a birdie at 13, where he chipped to about a foot and made the putt for birdie.
He birdied 15 from a bunker, sinking a five-foot putt, and birdied the par-three 16th after his tee shot landed two feet from the pin.
His birdie at 17 moved him to 19-under, making a bogey at the last meaningless.
"I am proud of the way I played coming in," Garcia said.
The victory helped erase the memories of his last appearance at Greensboro, when he held a share of the third round lead in 2009 but eventually finished fourth.
"That year, I was pretty much in control and I lost it myself," Garcia said, adding he didn't think the Sedgefield course owed him something. "The course didn't do anything wrong to me."
Clark, a local favorite after attending North Carolina State University, moved into a tie with Garica with a birdie at the eighth -- his third hole of the day.
Garcia edged ahead again with a birdie at the 11th, but after a bogey at 12 he was again tied for the lead.
American Chad Campbell briefly joined them atop the leaderboard with a third straight birdie at 17, but Garcia then launched his big run.
American Bud Cauley finished third with a 68 for 265. Campbell's 66 gave him a share of fourth place on 266 alongside Jimmy Walker (67) and Sweden's Carl Pettersen (68).
"It was going to be tough to catch (Garcia), the way he finished," Clark said.
Final-round scores on Monday in the weather-disrupted US PGA Tour Wyndham Championship (USA unless noted, par-70):
262 - Sergio Garcia (ESP) 67-63-66-66
264 - Tim Clark (RSA) 63-67-67-67
265 - Bud Cauley 66-65-66-68
266 - Chad Campbell 71-64-65-66, Jimmy Walker 66-62-71-67, Carl Pettersson (SWE) 62-68-68-68
267 - Nicolas Colsaerts (BEL) 67-65-69-66, Bill Haas 68-65-67-67, Jason Dufner 68-67-63-69
268 - John Merrick 66-69-67-66, Troy Matteson 64-68-68-68, Davis Love 67-66-66-69, Harris English 66-64-68-70
269 - Brendon de Jonge (ZIM) 68-68-67-66, Scott Stallings 64-70-67-68, Charl Schwartzel (RSA) 67-68-66-68, Richard H. Lee 66-69-65-69, Matt Every 65-66-68-70
270 - John Huh 69-65-69-67, Bobby Gates 69-67-65-69, Justin Leonard 68-68-64-70
271 - Chris Kirk 66-69-69-67, Angel Cabrera (ARG) 67-71-66-67, Trevor Immelman (RSA) 67-68-68-68, Graham DeLaet (CAN) 69-67-67-68, Rocco Mediate 70-65-68-68, Webb Simpson 66-63-71-71
272 - Rod Pampling (AUS) 68-66-70-68, Tim Herron 76-61-67-68, Brandt Snedeker 67-67-68-70