Claudio Ranieri felt Fulham succumbed to stage fright following Javier Hernandez's contentious equaliser in the eventual 3-1 loss to West Ham.
Ryan Babel's third-minute opener was cancelled out in controversial circumstances when Mexico striker Hernandez used his hand to bundle the ball over the line.
The match official failed to spot the infringement and the Hammers quickly grabbed a second through Issa Diop, before Michail Antonio sealed the result in second-half stoppage time.
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Ranieri believes the Hernandez incident underlines the importance of technology in football but conceded a lack of confidence crippled his team at London Stadium.