In contrast, West Ham were buoyant after snatching a draw that had not seemed remotely likely until substitute Hernandez popped up to score soon after coming on.
Evra, meanwhile, replaced the injured Aaron Cresswell in the second half and looked solid on his first appearance in over a month. "Stoke next Monday is our game of the season now".
The home side had dominated the London derby for 73 minutes, leading for nearly half that time after Cesar Azpilicueta poked home in following a short corner.
The Blues had chance after chance to kill the game off, but never took them and that gave the Hammers hope.More news: Lifter Punam Yadav wins gold at CWG
The teenager, who again played as one of three centre-halves, admitted he had tried to bone up on Antonio Conte's men as much as he could in advance but that he learned most on the job.
Chelsea and West Ham are on opposite sides of the capital and the Premier League table, but they were even on Sunday. About one point, but this is not the first time.
"I think with this game we can see our season", Conte told the BBC. I don't understand why after 1-0 we always drop and let the opponent get more ball possession.
West Ham are scheduled to face off against Stoke, Arsenal, Manchester City, Leicester, Manchester United, and Everton. Not for the first time Cesc Fabregas's crisp pass carved open the West Ham midfield, but as Hazard slipped Morata in the Spaniard had already moved beyond the last defender.
'We are creating a really good spirit in the team, right the way through, from the injured boys, the boys on the bench, we stick together on and off the pitch and Chelsea was a good example of that'. "He showed when he gets to that level of form, everyone knows he's very good". West Ham had mustered two touches in the opposition box prior to Javier Hernandez's strike, but Gary Cahill - on his return to the Chelsea team in place of Andreas Christensen - failed to cover himself in glory.