Atrás
Pedro Neto scored his first double in a Premier League game in what was his 187th appearance in the English top flight, but the focus was not on him at the full-time whistle.
The Portuguese showed good composure for both goals, which came in the opening minute of the second half and then the 90th minute, with 11 minutes added on after that.
Chelsea were good value for the win and threatened to add to their tally, most notably when Moises Caicedo's stunning volley hit the angle of post and crossbar.
Cole Palmer had six shots, including a clever lob from Morgan Rogers' through ball which landed on the roof of the net.
They will now wait for news of the injury affecting keeper Martinez, who went straight to hospital after being carried off the pitch. Belgian Penders, 21, made his Premier League debut when he came on.
Between them, the two goalkeepers helped Chelsea to their first clean sheet in the league since 17 January, ending a run of 22 games with conceding.