"I certainly didn't think I'd be here," Haas said. "Everything just happened so quickly."
He closed with a 2-under-par 70 for a three-round total of 207, then won on the first extra hole for his eighth senior circuit victory. Kite (68) had been 3-0 in senior playoffs.
There was a four-way tie for third at 208 at The Club at Savannah Harbor, an island layout in the Savannah River: Wayne Levi (70), Brad Bryant (70), Gil Morgan (67) and Mark James (70), the first-round leader.
Haas has nine wins on the PGA Tour and eight on the Champions Tour. This was the first time he defended a championship.
"My game has aged well," Haas said. "My ball striking has been consistent. But I'm a lot better putter than I used to be. I kind of wish I'd changed my putting style when I was younger."
It was only the fourth playoff in the 30-year history of the Legends event and first since the team of Dale Douglas and Charles Coody defeated Hugh Baiocchi and David Graham in 1998 at the Golf Club of Amelia Island in Florida.
The Legends, which spawned the Champions Tour, was played as a team event until moving to Savannah in 2003.
In the playoff, Haas and Kite drove into the fairway on No. 18, but Haas' ball landed in a soft spot and picked up a chunk of mud. Haas hit his second shot through the green. Kite, meanwhile, was on the par-4 in two but 56 feet from the pin.
Haas chipped within 3 feet, then Kite rolled his first putt within 5 feet of the cup, but his next putt spun out for bogey. Haas tapped in for the victory.
"I had two good putts on 18 in the playoff," Kite said. "But I had one little misread there at the end."
James and Levi appeared to have a shot at making the playoff, but both stumbled. James three- putted the final two holes. Levi needed a sand save on the last hole, but his putt for par spun out.
BMW Asian Open
SHANGHAI, China - Raphael Jacquelin of France won the BMW Asian Open for his second European tour victory, leading from start to finish for a two-stroke victory over Denmark's Soren Kjeldsen.
Jacquelin closed with a 1-over 73 for a 10-under 278 total. Kjeldsen also shot a 73 in the event co-sanctioned by the Asian Tour.
Still chasing his first win of the season, South African Ernie Els shot an even-par 72 to finish tied for fifth at 6 under. Els won the tournament by 13 strokes in 2005.