Izawa's career on the Japan Golf Tour developed quite slowly. His first win came in 1995, and he did not make the top ten on the money list until 1999, when he was thirty one years old. He went on to top the money list in 2001 and 2003. In the first of those years he set a record of ¥217,934,583 in earnings which survived though the 2004 season, and his dominant form in Japan lifted him into the top twenty in the Official World Golf Rankings. He has 16 victories on the Japan Golf Tour (tied 10th on the career wins list) and is sixth on the career money list (through 2009).