Trailing 1-0 in the 55th minute, the Dynamo (2-1-0) got the equalizer when Barnes scored on a header off Ricardo Clark's first MLS assist since 2009.
Creavalle provided the go-ahead score 7 minutes later during a scrum in front of the net following an Adam Moffat corner kick.
Darren Mattocks scored for the Whitecaps (2-1-0).
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