It was Swiatek's first final at the US Open tune-up event, and the six-times grand slam champion enjoyed the Toronto crowd chanting "Iga! Iga!" throughout the match on her way to victory, with a few Polish flags in the crowd.
Swiatek was sharp and fast on the hard court while Kazakhstan's Rybakina was her own enemy for much of the match.
Rybakina was broken twice in an opening set that also saw Swiatek save two break points to take command of the match.
The first set was marred by 12 unforced errors for 27-year-old Rybakina, who struggled to strike the ball cleanly.
The Australian Open champion could not weaponize her serve either, with just one ace in the match, and Swiatek broke her again in the second set to take a 3-2 lead.
Swiatek, 25, dropped the next game but closed out the final three with confidence, landing a clean strike on match point to end her title drought.
Fatigue may have caught up with Rybakina, who played three hours more than Swiatek at the tournament prior to their meeting on Thursday as her previous three matches went to three sets.
With the Canadian title, world No.8 Swiatek will return to the top five in the rankings.
