Auckland: China`s Zheng Jie won the rain-delayed Auckland Classic on Sunday after fourth seed Flavia Pennetta retired hurt when trailing 2-6, 6-3, 2-0.
The world number 20 had a medical time-out at the change of ends when leading 5-2 in the first set and called for the physiotherapist several more times in the match to work on an apparent back injury before eventually throwing in the towel.
Italian Pennetta`s withdrawal gifted 28-year-old Zheng her fourth WTA title and her first since 2006, while providing a welcome boost ahead of next week`s Australian Open.
Persistent showers washed out the final on Saturday and continued on Sunday, forcing the match to be moved indoors to a smaller stadium where Pennetta, Italy`s first top-10 player, quickly seized the initiative.
The 29-year-old broke Zheng twice to seal the first set and raced to a 2-0 lead before her pint-sized opponent roared back into the match by peeling off five straight games.
Zheng, a former semi-finalist at Wimbledon and Melbourne Park, held a nervous service game to clinch the second set and broke Pennetta early in the third before the Italian decided enough was enough.
Once China`s highest-ranked player ahead of French Open champion Li Na, Sichuan native Zheng`s ranking has dipped to 48th after a disappointing 2011. But she has shown strong form in the leadup to the year`s first grand slam, upsetting former world number two Svetlana Kuznetsova in the Auckland semi-final.