The Ferns won thanks to a terrific goal from striker Amber Hearn, who set her own history in the process. Hearn gathered the ball 35m out and steadied herself before chipping goalkeeper Wang Fei in the ninth minute.
It was her 30th international goal and one worthy of becoming the highest goalscorer in New Zealand women's football history when she surpassed Wendy Sharpe's record of 29 goals established 18 years ago.
It was an opportunistic strike in a game sorely lacking genuine scoring opportunities.
The match was largely played between the two penalty boxes but broke down too frequently as passes went astray or was intercepted and neither goalkeeper was particularly tested.
"I'm really pleased to back up the win on Sunday,'' Readings said. "I don't think we were as dominant [as Sunday] and China definitely stepped it up.
"When you get to the Olympics, you are never going to get it easy. Sometimes you have to dig out a 1-0 win.
"In the past we would have struggled [to hold onto the lead] but I think we have shown now this team has something different to teams in the past.''
Readings has encouraged them to play more football and they totally dominated the opening quarter of the match as they pinned China back in their own half and easily dealt with anything the visitors threw at them. But the game lost any fluidity as both sides regularly coughed up possession.
Hearn will receive the plaudits for her goal but just as important was central defender Abby Erceg, who continues to impress and will surely catch the eye of European clubs at the Olympics - if she wants them to.
The 22-year-old is tall, strong, comfortable on the ball and reads the game well and is good enough to play in one of the top leagues like the German Bundesliga where six of her Football Ferns teammates play. She signed a one-year contract with Espanyol in the Spanish Superliga as a teenager in 2009 but returned home soon after as she struggled to adapt and currently captains Adelaide in the Australia W-League.
Readings started with the same side that beat China on Sunday, in a clear sign he wanted to win the game, but rang the changes late in the match as he gave players the chance to push for Olympic selection.
They have their final opportunity to make the cut of 18 players in two internationals against Australia in Wollongong starting on Sunday before the squad is announced later next week.
Their unbeaten streak will be tested by an Australian side ranked 10th in the world but the Ferns will go there full of confidence after their double over China. And that is a precious commodity.
New Zealand 1 (Amber Hearn 9) China 0. HT: 1-0.
