Bencic broke Aiava at love to open the match, one of the six break points she converted, and was never really tested as the 18-year-old Australian made 24 unforced errors.
Swiss ninth seed Belinda Bencic made a strong start to her claycourt season with a 6-3 6-0 win over qualifier Destanee Aiava to reach the second round of the Charleston Open in South Carolina on Monday.
Aiava did well to fight off one match point but then double-faulted the next time the match was on the line to hand Bencic victory in 56 minutes.
Up next for the world number 21 at the green-clay event will be American Allie Kiick, who beat Frenchwoman Pauline Parmentier 6-3 6-0.
Former French Open champion Jelena Ostapenko, a runner-up here in 2017, dropped the opening game of her match but quickly righted the ship and dominated the rest of the way in a 6-1 6-4 win over Swede Johanna Larsson.
Latvian Ostapenko had seven double faults in the match but rounded into form as the match wore on before clinching the win by firing down an ace.
She will next face American Shelby Rogers, who was a 6-4 6-2 winner over Russia's Evgeniya Rodina in her first match back after being sidelined for more than a year by a knee injury.
Such was her relief at being fit and back on court again, Rogers succumbed to tears after winning the opening set.
"It's kind of embarrassing to be honest," the 26-year-old Charleston native told reporters.
"It was a great moment, I enjoyed every second of it -- even when I got broken. That's part of it. It's all those feelings I missed so much. The adrenaline, the nerves, the excitement, everything. You can’t recreate that outside of the arena."
Top seed Sloane Stephens will be in action on Tuesday when she faces Spaniard Sara Sorribes Tormo in second round action, while defending champion Kiki Bertens, the second seed, plays Italian qualifier Martina Trevisan.