PSG host relegation battling Le Havre on Saturday
The fourth seed, who has lost only two matches at Roland Garros since his debut in 2005, is now just one short of Margaret Court's all-time record of 11 titles at a single grand slam.
Nadal, who has now won 15 grand slam titles in total, was never troubled in a one-sided final.
He claimed the Musketeers Cup without dropping a set in the tournament for the third time, having lost only 35 games en route to achieving what has been dubbed 'La Decima'.
Wawrinka, who had won his three previous finals at a major, bowed out on the second match point when he sliced a backhand volley into the net.