Burnley boss Scott Parker conceded his side are "fragile" as their hopes of Premier League survival were dealt a further blow by a 2-0 loss to West Ham.
A poor first-half display from the Clarets saw them concede after just 13 minutes, with Crysencio Summerville clipping a finish over goalkeeper Martin Dubravka.
West Ham doubled their advantage before the half-hour mark, with forward Valentin Castellanos heading home from a fabulous delivery from El Hadji Malick Diouf.
This latest defeat leaves Burnley 11 points from safety and without a top-flight victory in 16 matches, with Parker admitting his team's mentality is suffering.
Parker told BBC Sport: "It was tough today and certainly the first half was tough.
"I don't think there was a lack of desire or passion. We're in a difficult moment. I think you can feel that and the stadium felt that.
"I think you see a team that is fragile at this present moment in time, for sure.
"We gave ourselves a mountain to climb and in the second half, we had numerous chances to crank up the pressure.
"We have just fallen a little bit short today for many reasons."
In stark contrast, West Ham have now won three of their last four Premier League matches, as many as they had managed in their previous 21 in the top flight.
The Hammers are just three points off 17th-place Nottingham Forest, but head coach Nuno Espirito Santo wants his side to avoid any distractions as they look to continue their strong run of form.
He said: "It was important to react from the previous match and the boys did fantastic work today. We were solid and strong in our box.
"We are still in the same situation; we have to focus on ourselves.
"We have to try and get this energy to London Stadium. Our fans were helping the team, it was so nice to see."
Summerville has now scored in his last five matches, becoming the first player to do so for the club since Jesse Lingard in the spring of 2021, with Nuno full of praise for the winger's all-round game.
The Portuguese said: "He is playing amazingly, not only the work he does scoring and assisting but also the way he moves on the pitch, helps the defence.
"He is in a nice moment."