Swiatek stuns Sabalenka to reach WTA Finals decider

Iga Swiatek.
Iga Swiatek (pic) has booked her spot in the WTA Finals decider by thrashing Aryna Sabalenka. -AP

Iga Swiatek has knocked out rival Aryna Sabalenka in the semi-final of the season-ending WTA Finals in Mexico, putting the world No.1 ranking within her reach ahead of Monday's (Tuesday AEDT) title match.

A cool and collected Swiatek converted on three of seven break points to win 6-3 6-2 on Sunday and set up a final showdown with American Jessica Pegula. And the Pole can end the year on top if she is able to hoist the trophy.

The current top-ranked Sabalenka ended Swiatek's WTA Finals campaign in the penultimate stage a year ago but lacked her usual lethal power in Cancun, as a flurry of forehand errors undermined her best efforts.

The match began on Saturday but officials were forced to suspend the affair with Swiatek up 2-1 in the first set due to inclement weather.

The former world No.1 wrested the momentum immediately when play resumed on Sunday, converting on a break point chance in the fourth game.

Sabalenka whacked her racquet in frustration after she sent a shot beyond the baseline to hand her opponent the break in the third game of the second set and Swiatek converted on another break point with a mighty overhead smash in the seventh game.

Swiatek pumped her fists and cheered wildly as Sabalenka sent one into the net on match point.

She next faces an in-form Pegula, who shredded the US Open champion Coco Gauff 6-2 6-1 to reach the title match. Pegula beat Swiatek in their last meeting in the Montreal semi-finals.