Moya, who won the first of his 18 ATP singles titles at the same event 10 years ago, needed only one hour 12 minutes to dispatch Argentina's Juan Monaco 6-1, 6-2.
The Spaniard now plays Mariano Puerta, another Argentine, in the quarter-finals.
Canas, who enjoyed the best season of his career last year by claiming three titles, fell 6-4 6-3
The Argentine's frustration got the better of him at the end of the first set when he was given an official warning for twice throwing his racket to the ground.