Cesc Fabregas' bizarre red card capped a wretched night for Chelsea as the champions were shocked 3-0 by West Brom.
Saido Berahino's double ended his own nine-game drought as he made it 20 goals for the season for the Baggies.
Chris Brunt added a third to compound Chelsea's miserable night in the West Midlands as their 16-game unbeaten league run ended.
Referee Mike Jones was taking control of a spat between Diego Costa and Gareth McAuley when Fabregas kicked the ball back towards the group.
The former Barcelona man was dismissed as a brace from Saido Berahino and Brunt's strike sealed victory for Albion.
He said: "Where is the danger of the situation, where is the aggression in the situation to get the red card in a friendly game?
"I really don't understand. I think (Darren) Fletcher was aggressive, he pushed him (Fabregas) in the chest because he is experienced and knows where he can push for a yellow card. He is much more aggressive than what Fabregas did.
"For me a top referee, a stable, big personality and in control of the game, goes there, two or three words and it's done. It's a bizarre red card.