Perth, Dec 31 (IANS): The women's World No.15 Zheng Qinwen improved to 2-0 in the new season after defeating the 119th-ranked Olga Danilovic 6-4, 6-2 at the United Cup in Perth. The victory sent the Group E tie between China and Serbia into a deciding mixed-doubles rubber.

Zheng will team up with Zhang Zhizhen with a chance to send China (1-0) through to the United Cup quarterfinals, having already secured a 3-0 sweep of the Czech Republic on Day 2. Serbia will put its hopes of winning its opening tie and remaining in contention on the shoulders of Danilovic and Novak Djokovic.

After men's World No.1 Djokovic opened the tie with a 6-3, 6-2 win over Zhang, Zheng was faced with a must-win match against Danilovic. Coming off a three-set win over reigning Wimbledon champion Marketa Vondrousova in her opener, Zheng kept her cool to keep the feisty 22-year-old Serbian at bay.

Bidding to tally her third career Top 20 victory, Danilovic jumped out to a 2-0 lead and found herself a point away from a 3-0 lead early in the first set. Zheng stormed back to take the next four games with the aid of a flurry of forehand winners.

The Chinese star appeared to have wrenched the momentum back for good, but Danilovic kept the pressure on. With Zheng serving for the opening set at 5-4, Danilovic earned two chances to level the set.

Zheng responded with steely resolve, wiping away Danilovic's chances and coming through an 11-minute game to take the 61-minute set with a leaping backhand winner.

Zheng rode out her momentum to a 4-0 lead in the second set and closed out the win with her eighth ace of the match after 1 hour and 37 minutes.

The No. 1 in the ATP Rankings Djokovic earlier eased past Zhang 6-3, 6-2 to give Serbia a 1-0 lead in its Group clash with China in Perth. Djokovic was rock-solid in all facets of his game as he notched a 74-minute triumph in his maiden Lexus ATP Head2Head meeting with Zhang.

Djokovic converted three of the seven break points he earned to delight the Serbian contingent in the stands at RAC Arena. He is now 17-1 in season-opening matches since the start of 2007.

“I was a little bit rusty in the beginning, a little bit out of rhythm in the first five or six games, but it’s normal,” said Djokovic. “When you don’t play an official match for over a month, it obviously takes a little bit of time to get the engines going and he was serving well. I think the serve was great on my part, whenever I needed to get myself out of trouble, at 15/15 or 30/30 in my service games, I found a good serve,” Djokovic said.