A number of factors were taken into consideration, including Erakovic's ranking, the fact she had beaten two top-16 players in the qualifying period - world No 2 Victoria Azarenka and No 15 Sabine Lisicki - has reached the last 16 in four WTA tournaments in 2012, including the final at Memphis in February, and her record on grass.
The 24-year-old, who will compete at Wimbledon next week, is ranked 45 in the world but will probably sit inside the top 30 at the Olympics once the full field is known. Countries are restricted to a maximum of four players in the singles and two in the doubles.
"I am thrilled to be selected,'' said Erakovic, who was beaten in the first round at the 2008 Beijing Olympics. "Representing New Zealand on the grass courts of Wimbledon at the Olympic Games is a huge honour and I am very excited.
"The grass time I get in now before and during Wimbledon will benefit me greatly for the Olympic Games and I am looking forward to joining our team in as little as over a month now.''
Erakovic was one of two athletes confirmed today, with weightlifter Richie Patterson selected for the 85kg division.
Patterson finished 21st in the 77kg class at Beijing in 2008 but will go into the event having won both the Oceania and Commonwealth Championships in June and after breaking six national records this year. He also picked up silver in Delhi two years ago.
The 29-year-old has designs on finishing inside the top 10 at London and also becoming the lightest New Zealander to clean and jerk 200kg.
The NZOC expect New Zealand's Olympic team to be around 185 - similar to the number who competed in Beijing - with the final cut-off set at July 9 as a handful of athletes race to meet the selection criteria.
The men's football team will be named tomorrow and the women's team next week, with the eventing team due to be announced on July 3 and the road cycling team in the next seven days.
The men's and women's basketball teams need to finish in the top three in their respective final qualifying tournaments to earn their ticket and a number of athletes including Sarah Cowley and Rebecca Wardell (heptathlon), Scott McLaren (decathlon), Andrea Miller (women's 100m hurdles), Jake Robertson (5000m) and Zane Robertson (1500m) still harbour hopes of qualifying.
Brent Newdick has met the B standard in the decathlon and is expected to be confirmed if McLaren fails in his bid to meet the standard this weekend.
The door has closed for women's RS:X boardsailing, open water swimming and wrestling.