In her short time as a professional tennis player, even as her career flourished and she established herself as one of the best in the world, Coco Gauff’s great progress was often overshadowed by the match-up she just could not solve. By last June, Gauff had lost 11 of her first 12 matches against Iga Swiatek, an opponent she is likely to play for many more years.

What was once a painfully one-sided non-rivalry may have finally turned into one of the best match-ups in professional tennis. On Sunday evening at the United Cup in Sydney, Gauff registered her second consecutive win over Swiatek, toppling the five-time grand slam champion 6-4, 6-4 after two hours of sublime tennis from both champions.

Gauff’s win over Swiatek, the world No 2, paved the way for the USA to win the United Cup for the second time in the tournament’s three years as they defeated Poland 2-0. After Gauff, ranked No 3, secured the first point for the USA, the men’s No 4 Taylor Fritz narrowly defeated the No 16 Hubert Hurkacz 6-4, 5-7, 7-6 (4).

After an extremely entertaining 10 days at the United Cup, the final women’s duel was the most anticipated match of all. It lived up to the hype in full as the pair combined to produce tennis of the highest quality throughout their two hours on court.

Gauff and Swiatek are undoubtedly the two best athletes on the WTA tour and as they both players desperately tried to dictate and control the baseline, they also defended spectacularly, chasing down balls that would be certain winners against any other player, resetting points and constantly flipping defence into a tack in the blink of an eye.

Although Gauff was the more solid and durable player in the opening set, Swiatek forced her way back into the match by taking an early break in the second set. As the quality of play skyrocketed throughout the set, Gauff thrived in the important points and she won the final four games of the match against an increasingly fatigued Swiatek.

Since hiring her new coach Matt Daly after the US Open in September, Gauff has made an incredible amount of progress in no time at all. She has addressed her two glaring issues head-on, adjusting her grip on her service motion and significantly improving her forehand.

In their previous encounters, Swiatek’s dominance over Gauff stemmed from her ability to dismantle and expose Gauff’s frail forehand with her own relentless pace and weight of shot, but Gauff’s forehand is now much better at both deflecting pace and piercing holes in her opponents’ defences with its heavy topspin, meaning the complexion of their match-up has changed. Gauff also defeated Swiatek in November en route to winning the WTA Finals in Riyadh and she will head to the Australian Open fully confident that she can defeat everyone in her path without exceptions.

“I have the belief that I’m one of the best players in the world. When I play good tennis, I’m hard to beat,” said Gauff.

As Gauff flourished, Fritz also picked up where he left off in 2024 after a career year that saw him break into the top four and reach his first grand slam final at the US Open. Despite a spirited performance from Hurkacz, in the most important moments deep in the third set tie-break, Fritz struck the ball with confidence and freedom as he closed out an excellent win.

“I want to thank my team, unbelievable support,” said Fritz. “The vibes all week were amazing. That’s one of the things that makes our team so great and one of the reasons why we’ve been able to do so well. We’ve just really come together. It’s amazing.”

Elsewhere, Naomi Osaka’s promising week at the Auckland Open ended in despair as she was forced to retire from her first final since 2022 due to an abdominal injury despite leading Clara Tauson 6-4. Osaka appeared to be in brilliant form by Sunday’s final as she rushed to a 5-1 lead in the opening set but her serve speeds abruptly fell and her level rapidly dropped. After holding on to close out the set, a tearful Osaka retired, making her a doubt for the Australian Open. Barbora Krejcikova, the reigning Wimbledon champion, confirmed she would miss the Australian Open with a back injury. Caroline Wozniacki and Karolina Pliskova are also among the no-shows at Melbourne.

In Brisbane, the world No 1 Aryna Sabalenka won her 18th career title by recovering from a set down to defeat Polina Kudermetova 4-6, 6-3, 6-2. Sabalenka has now won 27 of her last 28 matches in Australia with two Australian Open titles, this victory in Brisbane and a final in Brisbane last year. In the men’s draw, Jiri Lehecka won his second career title after Reilly Opelka was forced to retire while trailing 4-1 in the opening set.