brisbane: Novak Djokovic has overcome a wrist issue to defeat Jiri Lehecka 6-1 6-7 (7-3) 6-1 and send Serbia through to the United Cup quarter-finals. The world No.1 was troubled by his right wrist during practice on Tuesday morning, with the injury requiring intense treatment from his physio. Djokovic was cleared to play his singles match 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 in the tie. The 24-time grand slam winner was on track for an easy victory against Lehecka after winning the first set and shooting out to a 3-1 lead in the second. But with his wrist troubles growing as the match wore on, Djokovic started making a series of uncharacteristic unforced errors. Djokovic took a medical time-out after losing the second-set tiebreak, and he came out firing with a double break in the third set to seal victory. “I managed to play through,” Djokovic said of his wrist injury. “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 and let’s see what happens now.” With Serbia’s quarter-final spot already secured and Djokovic wanting to rest his wrist, the 36-year-old opted against playing in the mixed doubles. If Serbia win the mixed doubles, they will top Group C and meet Australia in the quarter-finals. That would pit Djokovic up against world No.12 Alex de Minaur, who showcased his potential with a devastating 6-4 6-2 win over world No.10 Taylor Fritz on Monday. If Serbia lose the mixed doubles, they will qualify for the quarter-finals as the best second-placed team in Perth, meaning they would then face Poland. Djokovic’s wrist didn’t look to be affecting him early. He broke Lehecka in the fourth and sixth games to wrap up the first set in 34 minutes, and the match looked a foregone conclusion when Djokovic raced out to a 3-1 lead in the second. Lehecka sprung to life to twice break Djokovic on the way to a 5-3 lead. Djokovic broke back to send it to a tiebreak, but a series of unforced errors handed Lehecka the set. The medical time-out after the tiebreak seemed to work its magic as Djokovic raced through the third set in 35 minutes. In the women’s singles, Vondrousova raced through the first set, but the world No.7 hit the skids in the second as Danilovic finally found her groove. Vondrousova thrived in the big moments of the third set to seal victory and give the Czech Republic a 1-0 lead. Danilovic converted four of her 10 break-point chances for the match, but Vondrousova was more efficient by converting six of her seven opportunities.