Peter Grant admitted the pressures of being in 'a results-driven business' led to him leaving his post as Norwich manager after less than a year in charge of the Championship club.
Grant, 42, left by mutual consent tonight after the 1-0 defeat at bottom club QPR yesterday left the Canaries in the relegation zone with just eight points from their opening 10 matches.
The former Celtic defender took over from Nigel Worthington in October 2006 and after only finishing 16th last season was expected to mount a promotion challenge this term.
He told the club's website: 'It was a very, very difficult decision for us to make but it was right for myself and for the football club to go forward.
'I have had fantastic support from the board from minute one right up until the time of leaving but we are in a results-driven business and I don't like being second best at anything.'
Grant suffered horrendous luck with injuries during his 12-month tenure at Carrow Road and was also hamstrung by the sale of key players Robert Earnshaw and Dickson Etuhu to Premier League sides Derby and Sunderland respectively.
But after luring last year's Championship top scorer Jamie Cureton back to his first club from Colchester in the summer Grant was expected to vastly improve on last year's showing.
But instead his side have failed to score in their last six matches in all competitions and have slipped to 22nd place in the table.
The Scot believes he could have had more luck but he believes the Canaries' season will pick up.
He said: 'Unfortunately for me I feel that the balls haven't bounced the right way for me over the last 12 months.
'But the most important things for me have always been the supporters and the club itself.
'They are the two constants while managers and players come and go.'
Chairman Roger Munby said in a statement: 'We had a long discussion with Peter after the QPR game in which Peter said that he felt he had been supported by the club in everything that he had tried to do at the Carrow Road.
'Therefore he felt he owed it to the board to be honest with himself and with us about whether he could turn things round.
'We would like to express our heartfelt best wishes to Peter and his family and wish him and them every success for the future.'
Coach Jim Duffy will take temporary charge of first-team affairs at Carrow Road with the next fixture not until the visit of Bristol City on October 20.