It was a day of high drama and shifting fortunes at the United Cup in Perth, as the defending champion United States faced a stern challenge from Argentina in Group A. The action-packed tie saw standout performances, unexpected upsets, and a display of true grit from both sides, setting the tone for what promises to be a fiercely competitive mixed-teams event.
For the United States, all eyes were on Coco Gauff and Taylor Fritz, both carrying the weight of expectations as top-ranked American stars. The day began with a jolt when Argentina’s Sebastian Baez, ranked No. 45 in the world, pulled off a stunning comeback to defeat World No. 6 Taylor Fritz in a three-set thriller. Baez, who had never previously beaten Fritz in five attempts, turned the tables with a 4-6, 7-5, 6-4 victory that spanned two hours and 35 minutes.
Fritz looked poised to continue his dominance over Baez early on. He took the first set 6-4, breaking Baez in the tenth game and then surging ahead with another break to lead 2-0 in the second. But Baez, a fixture in the ATP top 50 and known for his tenacity on clay, showed he had plenty of fight left on the hard courts of Perth. After breaking back immediately, Baez saved a crucial break point in the sixth game of the second set and then broke Fritz again to surge ahead 4-3. The American reeled him in, leveling at 5-5, but Baez snatched the set 7-5, setting the stage for a dramatic decider.
In the third set, Baez’s resilience was on full display. He broke Fritz for a fourth time, then held his nerve to close out the match with a simple volley into the open court. Despite blasting 23 aces to Baez’s four, Fritz struggled on his second serve and couldn’t convert enough break points, with Baez saving eight of the eleven he faced. "I am so happy right now," Baez shared after his victory. "We have been searching for this feeling for many years and I am happy to give this point to Argentina. Thank you to the crowd. I felt very comfortable today."
Fritz, meanwhile, opened up about his physical struggles during the offseason. He revealed to reporters, “I spent the majority — pretty much the entirety — of the off-season trying to rehab my knee tendinopathy, but that’s a thing that takes months and months to get better. I didn’t get to play a lot of points because I’m trying to not push it too hard. So, it’s just going to be a struggle of trying to get the reps in and get the points and matches in to start feeling like I’m comfortable, while still managing my knee pain, because I’m going to try to play through and keep doing the rehab while traveling and getting better. But if that doesn’t work in a couple of months, then I am just going to have to full stop and fix it.”
For Baez, the win was not just a personal milestone—his first ever ATP victory over Fritz in six attempts—but also a major boost for Argentina, who had already swept Spain 3-0 in their opening Group A tie. With Baez’s point on the board, the pressure shifted squarely to Coco Gauff, the world No. 3 and reigning United Cup champion, who was tasked with keeping the United States’ title defense on track.
Gauff faced Solana Sierra, the world No. 65 from Argentina, in what was Sierra’s first-ever top 10 matchup on the WTA Tour. Gauff wasted little time asserting her dominance, racing out to a 5-0 lead in the opening set. She saved two break points along the way and limited Sierra to just seven points on serve in the first set. After a brief wobble with two double faults, Gauff regrouped and reeled off four consecutive points to claim the set 6-1 in just thirty minutes.
The second set was nearly a carbon copy of the first, with Gauff dictating play from the baseline and showcasing her trademark athleticism. She broke Sierra repeatedly, closing out the match with another emphatic 6-1 set to level the tie at 1-1. “I feel like I can play even better too, which is even more exciting,” Gauff said on-court after her win. “It’s always tough starting the first match of the season, especially against an opponent like her and someone who played yesterday. I’m really happy with how I managed all those emotions.”
With the tie balanced on a knife’s edge, it all came down to the mixed doubles. Gauff returned to the court, this time partnering with Christian Harrison, to face Argentina’s Maria Lourdes Carle and Guido Andreozzi. The American duo quickly found their rhythm, dominating baseline exchanges and outmaneuvering their opponents at the net. After just 63 minutes, Gauff and Harrison sealed a 6-4, 6-1 victory, delivering the decisive point for Team USA and ensuring a 2-1 win in the tie.
This United Cup campaign marks the second consecutive year that Gauff has gone undefeated in singles for the United States, and her versatility in doubles continues to be a major asset for the team. The defending champions now move to 1-0 in Group A and will next face Spain, while Argentina, despite the loss, remains in contention for a quarterfinal spot after their earlier sweep of Spain.
For Fritz, the focus now shifts to managing his knee tendinopathy, as he withdrew from further play in the tie to avoid aggravating his condition. His powerful serving was on display, but the lack of match practice and ongoing rehab clearly impacted his movement and confidence on court. With the season just beginning, Fritz’s health will be a storyline to watch as the tour progresses.
Meanwhile, Baez’s heroics have given Argentina hope for a breakthrough United Cup campaign. The 25-year-old’s win over Fritz was his second hard-court victory of 2026, a significant improvement after winning just four matches on the surface all of last year. His ability to raise his level in big moments and save break points under pressure was the difference-maker on a day when the margins were razor thin.
After a rollercoaster start, the United Cup’s round robin stage is already serving up compelling narratives and memorable performances. With Gauff leading the charge and Fritz battling adversity, Team USA’s quest to defend their title is off to a dramatic start. But with Argentina hungry for their first quarterfinal berth in three attempts, and Spain looming as the next challenge, the group remains wide open. Tennis fans everywhere will be watching closely as the action in Perth continues to unfold.
As the United Cup heats up, both teams have shown they’re ready to fight for every point, every match, and every opportunity. The stage is set for more fireworks in the days ahead.