The flamboyant Englishman, Europe's talisman in the memorable Ryder Cup victory last month when he won all four of his matches, picked up his second title in the World Golf Championships, 12th on the European and third in Asia.
He carded eight birdies to overhaul a faltering Lee Westwood and Louis Oosthuizen, the joint third round leaders, before dropping a shot on the penultimate hole for a four-day total of 21-under-par 267.
South African star Ernie Els and the American trio of Phil Mickelson, Jason Dufner and Scott Piercy all shared second place in Asia's richest tournament and only World Golf Championships event in the region.
"It's been an amazing five or six weeks with the Ryder Cup and then coming here in good spirits," said Poulter, whose triumph was his first of the season.
"As well as I've played this year, it would have been a disappointment personally to have gone that year without winning, and for me and for how I played this year, it's obviously a great and fantastic feeling especially after the Ryder Cup to get my hands back on a great trophy like this.
"I knew that if I stayed patient I'd be right there at the end. It was a special day. I knew there was a good round of golf in me out there on that golf course; as we saw yesterday, if you start going low and get a number on the board then you're going to be hard to beat.
"I feel confident with the putter right now. It's so nice to get my hands on another trophy and get back in the winner's circle."
World number four Westwood looked solid on the front nine with four birdies and one double bogey but his bid for a first WGC title in his 41st start unraveled with three bogeys after the turn.
Two-time HSBC Champions winner Mickelson was in the thick of action throughout the day. Mickelson's hopes however ended when he made bogey on the par three 17th hole after a poor tee shot and chip for an eventual 68.
"It was just the worst swing of the week, actually, with that eight iron but it was a very tough pin to get to that I felt like I needed to make birdie. At the time I was two back and trying to make a two," said Mickelson.
"I tried to carve a few shots into some of the pins and wasn't able to get close enough to them to make birdies to catch him. But he (Poulter) played really well, and I felt like these four days, I played some good golf and I'll hopefully improve on it next week."
Els, who was returning to action after an ankle injury, signed off with a 67 to challenge Poulter. "Good week. I know where I came up short. I came up short yesterday on 15 and 16, and today on 14 a little putt I missed. I was in contention all week, so that was great," said the reigning Open champion.
Scores after round 4 of the 2012 WGC-HSBC Champions being played at the par 72, 7,301 Yards Olazabal Course course (a- denotes amateur):
267 - Ian POULTER (ENG) 69-68-65-65.
269 - Jason DUFNER (USA) 68-66-71-64, Scott PIERCY (USA) 68-68-68-65, Ernie ELS (RSA) 70-63-69-67, Phil MICKELSON (USA) 66-69-66-68.
270 - Louis OOSTHUIZEN (RSA) 65-63-70-72, Lee WESTWOOD (ENG) 70-67-61-72.
271 - Adam SCOTT (AUS) 65-68-71-67.
272 - Martin KAYMER (GER) 68-69-67-68.
273 - Bill HAAS (USA) 69-67-66-71.
274 - Hiroyuki FUJITA (JPN) 73-67-67-67, Marcel SIEM (GER) 71-70-66-67, Thorbjorn OLESEN (DEN) 71-65-70-68, Prom MEESAWAT (THA) 67-70-69-68, Brandt SNEDEKER (USA) 72-71-60-71.
275 - Nick WATNEY (USA) 72-72-69-62, Carl PETTERSSON (SWE) 70-68-66-71.
276 - Marc LEISHMAN (AUS) 73-68-65-70, Luke DONALD (ENG) 68-68-69-71, Gaganjeet BHULLAR (IND) 73-68-63-72.
277 - Thomas BJORN (DEN) 72-70-68-67, Thongchai JAIDEE (THA) 70-68-69-70.
278 - Keegan BRADLEY (USA) 71-68-68-71.
279 - LIANG Wenchong (CHN) 72-73-66-68, Scott HEND (AUS) 70-74-67-68, Peter HANSON (SWE) 66-71-73-69, Justin ROSE (ENG) 72-70-67-70.
280 - John SENDEN (AUS) 72-70-70-68, Bernd WIESBERGER (AUT) 72-72-68-68, Thomas AIKEN (RSA) 68-73-69-70, Gonzalo FDEZ-CASTANO (ESP) 71-67-69-73.