Fisher hit six birdies and now leads Lee Slattery by two strokes at Celtic Manor, with Chris Wood, Thongchai Jaidee and Fabrizio Zanotti a further stroke back.
Slattery, the overnight leader, carded bogeys at the third, sixth and eighth as he started in poor fashion, but recovered to finish with a level-par 71.
However, it is Fisher who is best placed to secure a much-needed win.
"Hopefully this will be the start of a big summer for me," he said.
"Last year was disappointing and so far this year, nothing has really happened."