The ninth-seeded Spaniard rolled to a 6-3, 6-4, 6-4 win over Germany's Florian Mayer on Tuesday in the first round of the Australian Open at Melbourne, Australia.
"For me is a great victory," Nadal said in his on-court interview. "Very happy to keep having chances to play here in Melbourne. Body is good, and that's the key."
Nadal won the 2009 Australian Open title, and he reached the final in 2012 and 2014.
After advancing to 20 Grand Slam finals from 2005-14 and winning four of them, Nadal struggled the past two years in the majors. He got to the quarterfinals in Melbourne and at the French Open in 2015, then failed to get past the fourth round in his next five major events. He hasn't reached a Grand Slam semifinal since winning the French Open for the ninth time in 10 years in 2014.
In other men's action Tuesday, third-seeded Milos Raonic of Canada experienced little difficulty in his opener, dumping Germany's Donald Brown 6-3, 6-4, 6-2.
A semifinalist in Melbourne last year, Raonic dispatched Brown in 92 minutes, never losing his serve. He won a dominant 19 of 26 net points.
Eleventh-seeded David Goffin of Belgium needed five sets to shake free of 19-year-old Michigan native Reilly Opelka, 6-4, 4-6, 6-2, 4-6, 6-4. Opelka, who is ranked 208th in the world, was appearing in the first Grand Slam event of his career.
No. 25 Gilles Simon of France took down another young American, 19-year-old Michael Mmoh, 6-1, 6-3, 6-3. Mmoh, who was born in Saudi Arabia, is ranked 190th.