At 13 she moved to train in Basel, Switzerland, because of the better training facilities and coaching.
When she was 15, Ivanovic spent four hours in a locker room crying after a defeat – the first that her new manager had witnessed.
She thought that Dan Holzmann would abandon her, thinking she wouldn't be good enough to become a professional tennis player. In 2004, she went 26–0 on the ITF circuit, and won all five events that she entered, two of them as a qualifier.
As a qualifier in Zürich, she overcame a 5–1 third set deficit along with two match points to defeat world No. She then debuted in the qualifying draw of a Major at the US Open, where she was defeated by Lioudmila Skavronskaia after winning the first set 6–1 and having two match points in the 3rd set.
Additionally during this time, she earned over $15 million in prize money, which is the 20th highest in the all-time rankings.