Stankowski and Chamblee finished on eight-under-par at 280, two in front of Nick Price and the overnight leader David Duval - and eight ahead of both Colin Montgomerie and Ian Woosnam, who closed with disappointing rounds of 73.
Stankowski, a 26-year-old Californian who won on the junior tour the previous week, was originally the sixth reserve for the tournament, but picked up the pounds 156,000 first prize after Chamblee dumped his second shot to the par-five 18th - the opening sudden-death hole - into the lake.
Woosnam and Montgomerie, first and second respectively on the European Order of Merit, could not repeat their third-round 68s and fell back into the pack. Two shots further back was Sam Torrance following a closing 70.
The other first-time winners since the start of March have been Tim Herron, Paul Goydos and Scott McCarron. They have all won places in the starting line-up at Augusta. The sole exception was Fred Couples' triumph over Montgomerie in the Tournament Players' Championship at Sawgrass last week.
Stankowski's victory means that this year's field will now be 94 strong, eight more than in the tournament won by Ben Crenshaw last April. The field includes 12 Europeans.
And, of course, Jack Nicklaus, who warmed up for the season's first major by winning the 100th professional victory of his career at Scottsdale, Arizona, on Sunday when he retained the Tradition title on the lucrative Seniors' tour.
He sealed his fourth win in the tournament with a second straight round of 65, seven under par, which gave him a 16-under aggregate of 272 - three better than the former US Open champion Hale Irwin.
n Kelly Robbins beat Val Skinner with an 18-foot birdie putt on the fifth play-off hole to win the LPGA tournament at the new Twelve Bridges club in Lincoln, California. Emilee Klein, Meg Mallon and Barb Mucha tied for third at 277, while Laura Davies' final round 70 gave her a 282 total and a share of 16th place.Reuse content