Coutts won the best-of-three final 2-0 after Mahaney, the lowest-ranked skipper in the competition, incurred costly penalties.
In Sunday's semi-finals Coutts eliminated the Australian, Peter Gilmour, 2-0. The 13th-ranked Mahaney caused a stunning upset by defeating the top-ranked defending champion, Dickson, 2-1.
In the first race of the final Coutts scored a one-second victory after Mahaney was penalised for a rule infringement when he was leading. Mahaney also had the upper hand in the second race, but was again penalised only yards from the finish to hand the title to the New Zealander.
Coutts earned dollars 32,250 ( pounds 16,700) along with his title and trophy.
WORLD MATCH RACING CHAMPIONSHIPS (Long Beach, Ca) Semi-finals: K Mahaney (US) bt C Dickson (NZ); R Coutts (NZ) bt P Gilmour (Aus). Final: Coutts bt Mahaney.Reuse content