Penetta, the number four seed, had not dropped a set at Stanley Street all tournament but was hampered by a right hip injury during today's match, which was held indoors for the first time in its history. She called it quits five minutes into the third set.
The match was scheduled for yesterday but was held over to today due to constant rain in Auckland, and the decision was made late this morning to hold it indoors.
Penetta, ranked 20th in the world, called a medical timeout when leading 5-2 in the first set and although she quickly wrapped up the set on her return, she was twice broken by Zheng in the second and held a long discussion with her coach at its conclusion.
Zheng, ranked 48th in the world, began slowly, as she did in her semifinal victory over Svetlana Kuznetsova, but put the unforced errors of the first set behind her to take advantage of Penetta's injury. It is her first title since 2006.
Penetta was beaten in the final of the doubles along with her partner Julia Goerges of Germany yesterday.
The final was watched by a crowd of only about 200 corporate guests. General admission tickets were refunded, with only about a dozen spectators staying to watch the match on a big screen at the centre court's "fan zone''.
