Sam Allardyce was left to rue a rare sloppy defensive display from his West Ham United side as they slipped to a 3-1 defeat at Stoke City on Saturday.
Defensive solidity has been a key feature of the Hammers' play as they have lifted themselves up the Barclays Premier League table since Christmas, but it deserted them on a frustrating afternoon at the Britannia Stadium.
Having led through Andy Carroll's early header, the Hammers harboured high hopes of making it a fifth victory in six starts, but Stoke fought back to level through Peter Odemwingie before the break.
Marko Arnautovic then gave the Potters a 69th minute lead before Odemwingie's second of the contest killed the visitors' challenge off late on,
Big Sam saw the loss as an opportunity missed with the Londoners unable to turn their early second half pressure in to anything meaningful.
He told West Ham TV: "Sitting there after 60, 65 minutes we were thinking we've had the opportunity to get another goal and we haven't quite taken it.
"Kevin Nolan's one was offside obviously and Andy Carroll had a great chance as well. We had them on the back foot in the second half, and the wind was helping us, which was very powerful today.
"All it needed was the back players to continue to concentrate on defending correctly and we'd have eventually got another chance to score, maybe taken it or if not come off the field on a 1-1, but unfortunately our defending let us down in the second half.
"We didn't need to defend very often either, so it's very upsetting that I didn't see the defensive side of our game come together today, when the attacking side was a lot better than it was against Everton.
"There was a lot more chances, a lot more creativity, a lot more pressure on the opposition, but two shocking defensive moments have cost us the game, as well as the referee not giving us a penalty."
The Hammers' sudden generosity came as a shock to Allardyce, who has become used to seeing his side stifle the opposition's threat.
He continued: "It was a massive surprise to me. I changed the team around today, one to try and freshen the team up, two to bring some of the players in to show they can deliver, like the lads have delivered before. They'll be looking at me and saying we've lost the game 3-1, so why did I make those changes.
"I'll have to say that I'd tend to agree with them after that, because had we kept that solidity in the the defensive unit that we normally do I believe we would have got a point at least .
"I know the referee has probably taken a goal away from us [by not awarding a penalty for Marc Muniesa's second half handball] but it's still no excuse for the defending for two goals we conceded in the second half."
Having got in level at the break, Allardyce thought the Hammers would make use of the conditions in the second half - and that was how it was panning out until Arnautovic's killer blow.
Allardyce explained: "We were saying at half-time let's use the conditions to our advantage, which we did because Stoke found it hugely difficult to get out of their own half. When that's the case you can keep probing and putting pressure on the opposition.
"When you put pressure on the opposition constantly they end up making a mistake. That mistake happened and fortunately for them Begovic got away with it.
"When he came so far out and mis-punched the ball, he just went a yard or so ahead of Kevin Nolan. Had he not done that. Kevin would have been onside for that goal, so he was fortunate to get away with that one."
West Ham still need to look over their shoulder with six points between them and the bottom three and the manager warned the job is not yet done.
He added: "There are nine games to go, and our points per game are diminishing again. We've played 29 games and only got 31 points.
"That cannot continue, we have to keep more points ahead of our games total and do that to try and secure our Premier League position as quickly as possible."