Frank Lampard ordered Chelsea to cut out the mistakes as his side scored a 93rd-minute equaliser to complete an astonishing comeback after trailing West Brom 3-0 at The Hawthorns.
The Baggies looked to be racing to a first win since returning to the Premier League after errors allowed Callum Robinson, twice, and Kyle Bartley to score before half-time.
But goals by home-grown players Mason Mount, Callum Hudson-Odoi and Tammy Abraham – the third deep into stoppage time – rescued a point for the big-spending Blues.
It was a dramatic end to an incident-packed game and Chelsea boss Frank Lampard, who has spent £200m-plus strengthening his squad this summer, said he had mixed emotions after the match.
Lampard looked furious slumped in his seat in the dugout after he had sent his players out early for the second half.
There was relief at the end but the Chelsea boss knows his side must improve if they are to challenge for honours this season.
“It is a big lesson for us,” said Lampard after Saturday’s game. It is two points lost at the end of the day – and that’s no disrespect to West Brom.
“It was mistakes – clear mistakes – that cost us. You can have as many meetings as you want but with those mistakes you give yourself a mountain to climb.
“There is a lot we can keep getting better at.”