Beating a world number one is a pretty big deal for most players because, for most players, it really doesn't happen that often. It happened for Iga Swiatek recently as she bested Aryna Sabalenka at the 2023 WTA Finals.
It was a pretty big win for her because it saw her to her maiden WTA Finals final, which will be played on Monday afternoon. This wasn't the first time Swiatek played a reigning world number one, though.
She spent much of the last year as world number one, which obviously prevented her from playing somebody who is number one, but before she became number one herself, Swiatek played Ashleigh Barty twice.
The Australian was number one both times, and both times, it was Barty who won the match. The first time it happened was back in 2021 when they played at the Madrid Open. It was an easy two-set win for the Australian.
The second time they played one year later at the Adelaide international, a match Barty once again won. She would retire not long after that, allowing Swiatek to emerge as the best layer in the world.
It's a shame we never got that battle for the number one rank because it could have been epic. The third time she faced a world number one was recently at the WTA Finals, and it was an easy win for the Polish player.
It's a win that allows her to possibly return to world number one, which will happen if she beats Jessica Pegula in the final in Cancun.
After numerous achievements, Swiatek has now added a win over a world number one to her tally, with probably more to come in the future. Unless she remains world number one for the rest of her career, that's a possibility, too.