Roberto Martinez said he was full of “pure anger” after a perceived refereeing injustice handed Chelsea a 3-3 draw with Everton.
John Terry scored a controversial late equaliser at Stamford Bridge after Everton had held both a 2-0 and 3-2 lead on Saturday afternoon.
The Chelsea captain was in an offside position before flicking the ball beyond keeper Tim Howard to snatch a draw in the eighth minute of stoppage time, with a minimum of seven allotted by the officials.
When asked by BBC Sport of his reaction over the goal, Martinez replied: “Anger, pure anger.
“It’s a clear-cut offside that should have been spotted. To make it worse, it’s 50 seconds over time. It’s something that’s not good enough.
“There is no explanation. It’s a big, big error.
“Terry was two yards offside in the box. It’s unacceptable.
“Refereeing-wise, you cannot justify, you cannot explain that level. The players are really down. It cost us two points.
“Maybe referees should have a bit more help, and technology. The whole ground should see how long is left on a big clock.
“It’s heartbreaking because I thought it was a terrific game of football.”
This is the second game this season where Everton have conceded a goal late in stoppage time to throw away a 3-2 lead, after Bournemouth did the same in November.
“Bournemouth was one part of football. I accept that, it’s part of the game. Today was unacceptable,” Martinez added.