Crewe picked up their fourth away win of the season.
Gradi said: “I felt if we’d beaten Port Vale (two weeks ago) we would be on our way to challenging for a play-off spot.”
He added: “Obviously the results since then have got us looking at the bottom half of the league, but we have still got enough time to put ourselves in the promotion picture.
“But we’ve got to keep doing what we did, improve our defending and steer clear of injury.”