Novak Djokovic received treatment for a wrist issue during his United Cup match against Jiri Lehecka on Tuesday but the world number one battled through for a 6-1, 6-7(3), 6-1 win that drew Serbia level with Czech Republic in the $10 million mixed team event.
Djokovic, who is gearing up for a tilt at a record-extending 11th Australian Open title this month, appeared to be bothered by his right wrist in practice and occasionally grimaced in the opening set at the RAC Arena.
The Serb had his wrist worked on by a trainer after the first set and Lehecka sensed an opportunity, winning the second set in a tiebreak.
Djokovic took a medical timeout before the start of the third set and came out firing, running up a 5-0 lead before sealing the match.
The 36-year-old said after the win that the wrist was sore.
"But I managed to play it through and it's not the first or the last time," he added. "These things happen. You just have to manage and find a solution."
"Let's see what happens now."
Djokovic had been scheduled to play in the deciding mixed doubles with Olga Danilovic but has been replaced by Hamad Medjedovic.
Wimbledon champion Marketa Vondrousova had earlier given the Czechs a 1-0 lead by beating Danilovic 6-1, 3-6, 6-3.
Greece were stunned by Chile in their Group B opener, with Maria Sakkari and Stefanos Tsitsipas losing 6-7(5), 6-3, 10-6 to Daniela Seguel and Tomas Barrios Vera in the mixed doubles decider at Sydney's Ken Rosewell Arena.
Sakkari beat Seguel 6-0 6-1 in the opener before Chile's Jarry downed Stefanos Sakellaridis 6-3, 3-6, 7-5 to level the tie after the Greeks decided not to field Australian Open runner-up Tsitsipas in the singles.
The Australian Open Grand Slam runs from Jan. 14-28 at Melbourne Park.
