Thorpe and Hatalsky finished regulation Sunday tied at 16-under 194 after a series of weather delays. They began the playoff and both parred the first extra hole before they decided it was too dark to continue.
When they resumed play Monday morning, both parred the second playoff hole, with Thorpe missing a nine-foot birdie putt.
At the third playoff hole, Hatalsky left his second shot in a greenside bunker while Thorpe put his second within five feet of the hole.
"It's a shame that we both played as well as we played and somebody's got to lose," said Thorpe, who won for the 11th time on the Champions Tour.
Thorpe shot a 3-under 67 in Sunday's final round, while Hatalsky had a 66 to force the playoff.