Top seed Stan Wawrinka won the Japan Open after thrashing Frenchman Benoit Paire 6-2, 6-4 in a one-sided final to capture his fourth title of the year.

French Open champion Wawrinka needed just 65 minutes to complete victory in Tokyo with Paire, who underwent a scan on his swollen left ankle before the match, clearly struggling.

Fierce pressure from Wawrinka earned the Swiss a break for 4-2 in the first set and he pressed home his advantage with a thumping crosscourt forehand which wrong-footed his close friend Paire.

With little left in the tank after toppling defending champion Kei Nishikori in Saturday's semi-finals, Paire took a tumble early in the second set but gamely battled on despite his obvious discomfort.