The British number two struggled on the American hard courts and in Asia but needed just 64 minutes to beat Belgian Wickmayer 6-2 6-1.
Watson took her chances impressively, converting all four break points, and won more than half the points on her opponent's serve.
Boulter, Norrie through in Miami - Watson out
She will face Estonian third seed Anett Kontaveit in the second round.
Watson fights hard but falls short against Kontaveit
Watson edges past Pliskova to reach second round