Nadal, seeded fifth, improved to 9-0 versus Wawrinka, the 15th seed, as he swept to the tournament title without dropping a set. Nadal lost just seven points over nine games serving Sunday and didn't see a break point.
Wawrinka managed to take only two points off Nadal's serve in the first set. Nadal opened the match by winning the first three points off Wawrinka's serve and taking the lead with a break in a 12-point game. Nadal then moved out to a 4-0 lead and posted a love-game in claiming the set.
Wawrinka stayed with Nadal through the first six games of the second set but had back-to-back double faults that handed Nadal a break and 4-3 lead. Nadal lost only other point on serve in finishing off the win.
He previously won the Madrid Open in 2005, when it was an indoor hard-court tournament, and 2010, when after it was moved to an outdoor clay court
Sunday marked the 55th career WTA title for Nadal, who has five championships in seven tournaments in 2013. He was runner-up in the other two events. The 55 ATP championships are 10th most all-time, one behind Ilie Nastase. Nadal is second -- to Roger Federer (76) -- among active players on that list.
Wawrinka, who won last week's tournament in Portugal, fell to 4-8 in ATP finals. He also has a runner-up finish this year.