Enticed by head-hunters at KPMG for the pound;98,000 post, he handed in his notice two years to the day after being recruited by Chris Woodhead, the last appointment made by the controversial chief inspector.
Mr Grix's arrival marked a significant shift to a more aggressive style of college inspection, which was taken over by OFSTED from the Further Education Funding Council following the Learning and Skills Act.
Heads rolled as principals of three of the first four colleges with low grades under pilot inspections left their posts. Mr Grix had warned of tough action and his new stance reflected the hardline approach being taken over failing schools.
Mr Grix told FE Focus: "I could not refuse the new post. I've wanted to be chief education officer for a long time, but it looked a bad risk. Now LEAs have demonstrated clearly that they are part of the long-term solution to education problems."
His deputy, Maureen Banbury, takes over until a new appointment is made by the incoming OFSTED chief inspector David Bell.
A report on North Derbyshire College this week will be seen as Mr Grix's swan song.
The college's future hangs in the balance after it became the latest to experience the heat of the new inspection regime.
"The quality of provision is not adequate to meet the reasonable needs of students," says its OFSTED report, due out today. "Five out of nine curriculum areas and the leadership and management of the college were judged to be unsatisfactory."
It added: "Few full-time students aged 16 to 18 sit GCSE and GCE A or AS-level examinations. Those who do are often unsuccessful. For example, the number of students enrolled on a GCSE mathematics course has declined from 63 in 199899 to just five in 20001. Of the five, only one obtained an examination grade higher than a D."