First-half substitute Danny Welbeck cancelled out Conor Gallagher’s early opener.
Welbeck had only been on the pitch for two minutes when he scored just before half time, played in by Pascal Gross.
Evan Ferguson was the player who went off injured, having had a decent chance a few moments before. The 18-year-old had also earlier crashed an effort against the cross bar.
Joel Veltman, who was booked after four minutes for a foul, also went off injured about 10 minutes before Ferguson. Julio Enciso came on for Veltman just before the half hour.
Kaoru Mitoma had just glided through the Chelsea defence but saw his effort well saved by Chelsea keeper Kepa.
It wouldn’t be match day if Albion hadn’t had some VAR drama.
Gallagher almost certainly handled as Pervis Estupinan crossed then Trevoh Chalobah appeared to have impeded Lewis Dunk in the penalty area.
But again nothing from ref Rob Jones or VAR.
