GLASGOW, September 29, 2013 (AFP) - Having completed a final round of 67, Howell saw overnight leader Uihlein fail to sink a 15-foot birdie putt on the 18th hole at St Andrews that would have given the American the title.
With the pair tied on 23 under par, the match went to a sudden death play-off and 38-year-old Howell prevailed on the second hole when he sank a birdie putt from eight feet after Uihlein had left his own putt inches short.
"It's incredible. The sun is shining and the crowd have come out," said Howell, who had lost all four of his previous play-offs.
"I have never played in an Open Championship here, but to win a golf tournament as a professional at the Home of Golf is quite amazing and I am really thrilled.
"I was really nervous all week and strangely less nervous today. I can't explain that at all. I stayed calm and smooth under pressure and that was really pleasing.
"It's been a long, long road from the depths of despair. I have had a lot of support from people around me and this is as much for them as it is for me."
Ireland's Shane Lowry and Englishman Tom Lewis missed out on competing in the play-off by a shot, with Lewis carding a superb final round of 64 and Lowry a 68.
It had been a dramatic tournament for 24-year-old Uihlein.
In the second round at Kingsbarns he missed scoring the first 59 on the European Tour by inches as his putt on the final hole drifted left.
The following day at St Andrews he holed a 47-yard wedge shot for an eagle on the final hole.
"Hats off to David, he played great, made a nice birdie in the play-off and congratulations to him. He made more putts than I did at the end of the day," said Uihlein.
"I just didn't make the putts when I needed and that's the way it is."
Selected scores after the final round of the Alfred Dunhill Links Championship at St Andrews, Carnoustie and Kingsbarns in Scotland on Sunday (GBR and IRL unless otherwise stated; par 72):
265 - David Howell 67 68 63 67 (won at second play-off hole), Peter Uihlein (USA) 71 60 65 69
266 - Shane Lowry 68 66 64 68, Tom Lewis 64 65 73 64
267 - Tommy Fleetwood 65 66 69 67
268 - Garth Mulroy (RSA) 66 69 65 68
269 - Ricardo Gonzalez (ARG) 67 69 63 70, Chris Wood 66 69 69 65, Charl Schwartzel (RSA) 68 68 66 67, Martin Kaymer (GER) 69 66 63 71, Thomas Levet (FRA) 68 64 68 69
270 - Hennie Otto (RSA) 68 63 69 70, Morten Orum Madsen (DEN) 66 74 66 64, Chris Paisley 72 62 66 70, Darren Clarke 69 66 66 69, Bernd Wiesberger (AUT) 70 65 67 68
271 - Ernie Els (RSA) 69 65 64 73, Pablo Larrazabal (ESP) 70 68 63 70, Scott Jamieson 71 65 67 68
272 - David Horsey 66 70 65 71, Paul McGinley 70 68 67 67, Christopher Doak 70 67 63 72, Julien Quesne (FRA) 69 66 67 70
273 - Joost Luiten (NED) 67 63 68 75, Alejandro Canizares (ESP) 69 65 70 69
Selected others:
277 - Padraig Harrington 76 66 64 71
278 - Paul Casey 74 67 62 75
282 - Retief Goosen (RSA) 70 68 68 76