That’s according to Baggies boss Tony Pulis who believes the Spaniard is in sensational form in the Premier League.
The victory for Chelsea means it is now nine on the bounce for Antonio Conte’s side who sit top of the table.
“The goal was disappointing because Gareth should have dealt with it, but I have got no qualms with him,” Pulis said.
“To get beat by that one mistake – and it’s a wonderful goal from Costa – is so disappointing, but we move on.
“To get beat by that one mistake – and it’s a wonderful goal from Costa – is so disappointing”
West Brom boss Tony Pulis
“Our structure and organisation was very good. One mistake, one chance and the fella puts it away – that is the difference in quality that separates the teams at the top.
“It is disappointing because Gareth has got to deal with it. He’s made a mistake and we move on. We don’t really want to criticise anyone.
“They are a very hard working group of players – I’m very disappointed for them.
“Our supporters will go home very disappointed, but having watched a very honest, hard-working team that very nearly pulled it off.
“I was happy all the way through the game. They play a different shape system to most teams in the Premiership. We had a good week to work on it.
“We were well set up without possession and caused them some problems on the break, particularly in the first half.”
West Brom will have an immediate chance to bounce back when they face Swansea.