Novak Djokovic's sore right wrist holds up to beat Lehecka, Serbia advances at United Cup

PERTH, Australia (AP) — Novak Djokovic endured a wrist injury to lead Serbia into a United Cup mixed teams quarterfinal showdown against host Australia.

The world No. 1 was troubled by his right wrist during practice on Tuesday morning and he received intense treatment from his physio.

Djokovic was cleared to play his singles match against Jiri Lehecka later in the day, and it was just as well given that Wimbledon champion Marketa Vondrousova defeated Olga Danilovic 6-1, 3-6, 6-3 to give the Czech Republic a 1-0 lead.

Djokovic looked on track for an easy victory against Lehecka while leading by a set and 3-1. But with his wrist troubles growing, Djokovic started making unforced errors. He took a medical timeout after losing the second-set tiebreak and came out strongly with a double break in the third set to win 6-1, 6-7 (3), 6-1.

“I managed to play through,” Djokovic said. “It’s not the first time or the last time, these things happen. You just have to manage. You have to find a solution and thankfully I managed to finish the match.”

There was confusion after the match as to whether Serbia qualified for the quarterfinals. Officials initially said that even if Serbia lost the mixed doubles and the tie, it would still advance as the best second-placed team in Perth. But organizers later clarified that Serbia would be out if it lost the mixed doubles in straight sets.

Serbia won the mixed doubles without Djokovic and topped Group E. They will take on Group C winner Australia on Wednesday in a quarterfinal in Perth. Poland will face China in the other Perth quarterfinal.

In Sydney on Tuesday, Chile defeated Greece 2-1.

Stefanos Tsitsipas — runner-up at last year’s Australian Open — was scheduled to face Chile’s Nicolas Jarry in the men’s singles but withdrew with a back injury. He was replaced by 19-year-old Stefanos Sakellaridis, who lost to Jarry 6-3, 3-6, 7-5 to level the tie.

Tsitsipas and Maria Sakkari then lost to Daniela Seguel and Tomas Barrios Vera 6-7 (5), 6-3, 10-6.

Chile leads the group ahead of Canada, which plays its final group game on Wednesday against Greece. Greece needs to beat Canada to have any hope of advancing to Thursday’s quarterfinals in Sydney’s Ken Rosewall Arena.

Norway advanced to the last eight in Sydney after Croatia won against the Netherlands 2-1. Norway topped Group F on countback after all three teams ended up with 1-1 records and 50% sets won.

Croatia would have topped the group had it swept the tie. Borna Coric edged Tallon Griekspoor 7-6 (4), 6-4 and Donna Vekic made it 2-0 by beating Arantxa Rus 6-2, 3-6, 6-1. However, Wesley Koolhof and Demi Schuurs spoilt Croatia’s plans when they defeated Ivan Dodig and Vekic 6-7 (3), 6-3, 14-12.

"I managed to play through," Djokovic said of his injury. "It's not the first time or the last time, these things happen. You have to find a solution and thankfully I managed to finish the match and let's see what happens now."

With Serbia's quarterfinal spot secured and Djokovic wanting to rest his wrist, the 36-year-old opted against playing in the mixed doubles.

If Serbia wins the mixed doubles, it will top Group C and meet Australia in the quarterfinals. That would also mean China would receive a quarterfinal berth as the best runner-up in Perth, eliminating the defending champion United States from further play.

If Serbia loses the mixed doubles, it will qualify for the quarterfinals as the best second-place team in Perth, and a quarterfinal Wednesday in Perth against Poland. China would then win the group and play Australia.

At Sydney in the first of two ties on Tuesday, Chile defeated Greece in the mixed doubles to claim a 2-1 win.

Stefanos Tsitsipas — runner-up at last year's Australian Open — was scheduled to face Chile's Nicolas Jarry in the men's singles match but pulled out at the last minute with a back injury. He was replaced by 19-year-old Stefanos Sakellaridis, who lost to Jarry 6-3, 3-6, 7-5 to level the tie.

But Greece won the mixed doubles in three sets to move into first place in its group ahead of Canada, which plays its final group game on Wednesday against Greece.

Maria Sakkari had given Greece a 1-0 lead with a 6-0, 6-1 victory over Chile's Daniela Seguel. Sakkari took just 26 minutes to wrap up the first set in the morning session at Sydney's Ken Rosewall Arena.

"I don't feel match sharp but I feel good," Sakkari said. "I'm very happy to have given my team the first point and I have full belief in the team so I'm super excited for what's coming."

Netherlands, 1-0, was scheduled to play Croatia, 0-1, in the late match in Sydney.