Iga Swiatek took less than an hour to regain her world number one spot after sweeping aside Jessica Pegula 6-1 6-0 in the final of the WTA Finals in Cancun.The 22-year-old Pole proved far too strong for the fifth-seeded Pegula in a final held over to Monday due to persistent bad weather during the tournament.Pegula had started solidly on her own serve but swiftly unravelled, as Swiatek ruthlessly punished her American opponent's errors to break twice in succession then serve out to love to take the opening set.Further unforced errors gifted Swiatek the opening game of the second set and by the time Pegula was broken again – this time to love – to fall 3-0 behind, her body language already indicated the tie was all but over.Pegula fashioned her first and only break point of the match when Swiatek served for the title at 5-0, but hit a backhand into the net and the Pole duly served to take the title with 59 minutes on the clock.Her victory sealed a sixth WTA title of the year for Swiatek, who also won her third French Open, while Pegula will end a year that saw her reach two grand slam quarter-finals ranked fifth.It concluded a troubled tournament which drew criticism from the eight leading women players for its problematic build-up, with the temporary venue only completed with one day to spare.