Oldham boss Paul Dickov was left to rue his side's second-half naivety after the Latics lost 4-1 at Yeovil in League One.
Jose Baxter headed Dickov's side in front after three minutes at Huish Park on Saturday but Gavin Williams' double - the first from the penalty spot - turned the game on its head before half-time.
James Hayter made it 3-1 before substitute Robbie Simpson was sent off and then Paddy Madden completed the scoring late on for the Glovers.
Dickov said: "We started well and got the goal, but then we got done by a penalty and a quick break. Up until that point we had coped with them quite well.
"At half-time we told the players to tighten up a bit defensively and we were confident we could get something out of the game. We had chances and balls cleared off the line, but with one break we found ourselves 3-1 down.
"We were looking to score the equaliser and try and get back in the game but one slip has let them in.
"We've been beaten 4-1 but I think we should have taken something out of the game. It's a strange one, but the goals we conceded were really poor.
"I think we had plenty of chances to win the game, but defensively when you are putting all of the pressure on, you need to think the worst. We didn't do that on four occasions and paid for it."