Costa showed more clout after the final whistle than he had in front of goal during the previous 90 minutes after punching the tunnel wall as he stormed off
The snarling Spaniard squared up to Baggies keeper Boaz Myhill at full-time, having earlier been involved in an angry exchange of words with defender Jonas Olsson
He also tried to get Claudio Yacob, who was already on a yellow card, sent off for tripping him over
When Hiddink took over as Blues boss he told Costa to channel his emotions in a positive way, and the forward responded with four goals in his last three matches
But after fluffing an early chance Costa was back to his antagonistic worst, picking fights all over the pitch despite having been booked for a late challenge on Craig Gardner
Hiddink said: " How close to the line was he? I think there was little space left
"But no, they were challenging each other
The defenders, and that's their right, were provoking him a little bit, but in a mutual way
Those clashes are normal
I didn't see any bad things
"A hole in the tunnel wall? We can repair that easily, it's not a problem
"He's an emotional guy and I like that very much
If you have to push players it's difficult to survive in the Premier League, but if you have to control them it's much better."
Chelsea had taken the lead after 20 minutes when Cesar Azpilicueta arrived at the far post to tuck in a cross from Branislav Ivanovic
Substitute Gardner equalised in the 33rd minute after collecting a stray pass from Pedro and firing home from 20 yards
In the 73rd minute Gareth McAuley deflected Willian's cross into his own goal but the Baggies snatched a point, and put another dent in Chelsea's already slim hopes of reaching the top four, when James McClean drove home four minutes from time
"We have said before that as long as it is possible mathematically to get fourth place then we will go for it," added Hiddink.
"But then we have to win all our home games at least
You need to average 2.8 points per match - so you have to win your games at home."
West Brom remain three points ahead of the Blues, but manager Tony Pulis is still totting up the points in order to achieve a different target.
"Now we need another 13 points to get to 40," he said
"But it's such a relentless league, every game is tough.
"We have tremendous respect for Chelsea but I felt we could do certain things to get something out of the game.
"So I'm very pleased we have got something out of it because the lads worked hard as a team and as a group to take something out of the game."
Source : PA
Source: PA