Oldham manager Paul Dickov was once again left frustrated as Coventry snatched their first league win of the season at Boundary Park on Saturday.
The Latics suffered their second defeat in as many games when sub Cody McDonald scored in the last minute of the game.
McDonald won the points for Coventry with a close range header at the near post from on loan defender’s Jamie Reckford left-wing cross.
Dickov told the club’s website: “We’re all frustrated.
“Like the previous three games, I’m talking about us being the better team, probably deserving to win the game and us getting nothing out of it.”
Having not kept a clean sheet in four games, Dickov was also unhappy in the manner in which his side conceded.
“It was an unacceptable goal to concede,” he said.
”A little bit of luck didn’t go our way, but when you’re struggling a bit you have to make sure you defend properly.
“I’m talking about basic defending and we work on these things every day, so we need to take them into games.”
Oldham could have ended up with a heavier defeat as in the fourth minute of stoppage time Dean Bouzanis pulled of a double-save to deny David McGoldrick and McDonald.
Latics travel to newly promoted Crewe on Tuesday hoping to end their four game winless run.
Both sides have not tasted victory since September 1.