Hanson's win was the fourth of his European Tour career and second this year. His victory in the Iberdrola Open Mallorca this season also came after a playoff.
Hanson held the lead after three rounds but struggled Sunday, shooting a 2-over 74 to fall into a three-way tie with Lawrie (66) and Boyd (68) at 10-under 278.
Missing the playoff by a single shot was Anthony Wall, who carded a 5-under 67 to end alone in fourth place at 9-under 279.
Julien Guerrier (69) and Simon Dyson (72) finished knotted in fifth at minus-8.