Greece make winning start as Baez, Sierra set up a clean sweep for Argentina in opener

Stefanos Tsitsipas found his winning touch on his return to action from injury as he led Greece to a 3-0 win over Japan on Friday in group play at the ATP-WTA United Cup.

The former world number three dispatched Shintaro Mochizuki 6-3, 6-4 in singles as he played his first match in almost four months after a recurring back injury forced him to take a break from the sport.

“I’ve had a lot of uncertainty, I didn’t know if I could compete,” Tsitsipas said. “But to play at this level is something I’m very grateful for.

“I’m healthy and that’s the most important thing in the world. I hope this tournament can give me some confidence before the Australian Open (January 18-February 1),” added the 27-year-old two-time Grand Slam finalist.

Team-mate Maria Sakkari began the tie with a 6-4, 6-2 defeat of Naomi Osaka.

Japan’s former world number one is suffering with a head cold and played far from her best in Perth.

“I was not operating at the percent I would want, I did not play amazing,” the four-time Grand Slam champion said.

“Honestly, it was not a bad first match for what it was. I’m thankful I have another to play. I need to not be afraid of making mistakes.”

Tsitsipas and Sakkari then teamed up for Greece’s dead-rubber mixed doubles tie to beat Japanese duo Yasutaka Uchiyama and Nao Hibino 6-2, 6-3.

Earlier, Argentina made a winning start after picking up the first team win by beating Spain in their opening match in Perth on Friday.

Singles victories by Sebastian Baez and Solana Sierra gave them a 2-0 lead before Guido Andreozzi and Maria Lourdes Carle won the mixed doubles match to secure a comprehensive win.

World No. 66 Sierra clinched the win for her country in Group A with a 6-4, 5-7, 6-0 triumph over Jessica Bouzas Maneiro after Baez defeated Jaume Munar 6-4, 6-4 in the first match of the competition. Guido Andreozzi and Maria Lourdes Carle then downed Yvonne Carvalle-Reimers and Inigo Cervantes 7-6(6), 6-2 in the mixed doubles rubber to earn Argentina a resounding 3-0 triumph.

Argentina are hoping to advance from the group-stage play for the first time in three tournament appearances, and were aided in their opening win by its second-highest and highest-ranked players in the ATP Rankings and WTA Rankings, respectively. But Sierra’s grit in particular was a highlight over 2 hours and 2 minutes, as she regrouped emphatically after losing a 5-2 lead in the second set.

Sierra was two points away from a straight-sets victory twice in the second set, having 30-30 serving at 5-3, and on return at 5-4. But when all was said and done, she needed three sets to top the World No. 41 and earn her third career win over a Top 50 opponent. She lost just eight points in the third set after dropping five straight games to lose the second.

In the first match of the 2026 ATP Tour season, World No. 45 Baez defeated Munar to give Argentina a 1-0 lead. Making his debut at the mixed teams event, the 24-year-old Baez recorded a 6-4, 6-4 win against the Spaniard in one hour and 43 minutes in the Group A tie. With the victory, he improved to 2-0 in the pair’s ATP head-to-head series.

After both players traded breaks early in the first set, Baez gained control at 4-4 by breaking Munar and serving out the set in the following game. In the second set, the Argentine showed great composure again by breaking back, immediately after losing serve, for a 4-3 lead. He saved four of the six break points he faced in the match, according to ATP Stats.

Venus gets Australian Open wildcard: Seven-time major singles champion Venus Williams was handed a wildcard to the Australian Open aged 45 on Friday, becoming the oldest woman ever to play at the season-opening Grand Slam.

The American, who has played only a limited number of singles matches in recent years, will compete in the main draw at Melbourne Park for the first time since 2021.

“I’m excited to be back in Australia and looking forward to competing during the Australian summer,” said Williams.

Agencies