Winston Reid insists the belief has returned to the West Ham squad following their last-gasp win over Sunderland.
Defender Reid was an unlikely match-winner when, four minutes into injury time, he collected Dimitri Payet's square ball on the edge of the area and rifled home through a crowd of players.
The late, late strike made it back-to-back 1-0 wins for the Hammers after a miserable run of five games without a victory.
It also provided their second win of the season at their new London Stadium, where West Ham have struggled since making the switch from Upton Park.
'It was really good for us,' said Reid. 'We needed the win, especially at home because we haven't been doing well lately at home, so it was very important.