Djokovic delivers as Serbia rally past China in United Cup

Serbia's Novak Djokovic closed out his spectacular 2023 on a winning note as the world number one eased past China's Zhang Zhizhen 6-3, 6-2 at his United Cup debut on Sunday before doubling up to secure a 2-1 victory for his side. However, Chinese youngster Zheng Qinwen took a win from Olga Danilovic 6-4, 6-2.

The 24-time Grand Slam winner showed no signs of slowing down as he lifted the Australian, French and U.S. Open trophies last season, surpassing Spain's Rafael Nadal for the men's record. His only blip was suffering a five-set defeat in the Wimbledon final, but that didn't get in the way of him securing the top spot at the year-end ATP Finals.

In another match-up in Perth, Taylor Fritz and Jessica Pegula combined to help defending champions United States beat Britain 2-1 in Group C as they overcame Neal Skupski and Katie Boulter 1-6, 7-6(4), 10-7 in the mixed doubles. The Americans can book their place in the quarter-finals of the $10 million team event that features 18 countries with a win over Australia on Monday.

Boulter continued her strong start to the season after an opening win over Australia's Ajla Tomljanovic as she clawed her way back from a set and 3-0 down to quell world number five Pegula 5-,7 6-4, 6-4 and put Britain up 1-0. Fritz dragged his team into contention as he managed a left thigh problem to beat Cameron Norrie 7-6(5) 6-4.

In Sydney, Canada earned a 2-1 win over Group B opponents Chile with Steven Diez and Leylah Fernandez beating Tomas Barrios Vera and Daniela Seguel 7-5, 4-6, 10-8. Fernandez subdued Seguel 6-2, 6-3 in the tie's opener before Nicolas Jarry won 7-5 6-4 against Diez, who had stepped in for Canadian number one Felix Auger-Aliassime.

(With input from Reuters)