The has explained how and why managed to overtake as the world No. 1, even though neither woman competed last week.

Fans were baffled when they woke up to see Swiatek dethroned from the top spot when she wasn't defending any points in this run of the rankings.

It has emerged that both women were hit with penalties for failing to play the required number of tournaments, with Swiatek getting a bigger blow than Sabalenka and losing her world No. 1 spot as a result.

Sabalenka and Swiatek have been in a tight battle for the world No. 1 ranking and fans were expecting to see them play for the top spot at the upcoming WTA Finals.

The Belarusian managed to close the gap after winning the WTA 1000 in Wuhan on October 20. It meant that, in last week's rankings, she stayed in second place just 69 points behind the five-time Grand Slam champion.

Neither woman competed last week and they were not defending any ranking points from 2023 so their positions were expected to stay the same. So there was confusion when the WTA announced Sabalenka had returned to No. 1 and dethroned Swiatek on Monday.

As of October 21, Sabalenka has 9,706 points while Swiatek has 9,665. The women's tennis tour has now confirmed that this is because of a rule penalising players who don't fulfil the requirements of playing six WTA 500 tournaments in a season.

There are zeros applied to their ranking for each one missed. Swiatek competed in two eligible 500-point events this year - the United Cup and Stuttgart. Meanwhile, Sabalenka played four - Brisbane, Stuttgart, Berlin and Washington DC.

Last week's Ningbo Open, which neither player entered, was the penultimate WTA 500 of the season and one of their last chances to fulfil the requirements. Because they didn't play, they were docked ranking points to "apply" the zeroes for the missed WTA 500s.

This week, because there is only one WTA 500 left for the season, the rivals are beginning to "see the impact" of skipping the mandatory tournaments. Sabalenka dropped 10 points from her opening-round Dubai exit earlier this year while Swiatek lost 120 from her last 16 exit in Miami.

And they will both receive another penalty next week to zero out their points at the conclusion of the WTA 500 Tokyo. Sabalenka will lose 65 points while Swiatek will be docked 195.

It means the Belarusian will extend her lead at the top with a total of 9,641 points to Swiatek's 9,470 by the time they get to the year-end WTA Finals in Riyadh.

The world No. 1 ranking will be up for grabs with both women expected to compete in the season-ending championships from November 2.

As the reigning champion, Swiatek is defending 1,500 points while Sabalenka has 625 to defend. The WTA Finals is set to be the Polish star's first tournament since the . She skipped the Asian swing after making a major coaching change.

after three years together and , the 'super coach' who recently split with and has also worked with the likes of and Victoria Azarenka.