Roberto Martinez hit out at referee Mike Jones for the "diabolical decision" of allowing John Terry's 98th-minute goal to stand and earn Chelsea a 3-3 draw with Everton.
Substitute Ramiro Funes Mori looked to have won the game for Martinez's side when he scored in the 90th minute, but there was still time for Terry to restore parity.
The Everton coach was furious that the game had gone beyond the allotted seven minutes of stoppage-time - the figure settled on following an injury to Bryan Oviedo - and that an offside against the Chelsea centre-back from Oscar's flick-on went unnoticed.
"It was a fantastic game for the fans, but the level of refereeing was diabolical. That's really hurtful and no-one deserves that," Martinez said on Sky Sports News.
"It's down to the decision and anyone from Chelsea would tell you that was offside. It's also well over the [allotted] time.
"That's something that's clear-cut, it's not just the referee's decision, it's something that's black and white.
"We scored two very good goals, get a two-goal lead and then it goes a bit frantic and opens up.
"Getting to that point and showing that character, that incredible resilience to get that winner - that's what we deserved, but it's been taken away in an unfair manner."
Speaking at a post-match media conference, Martinez suggested the introduction of technology is necessary to assist officials in getting borderline decisions accurate.
"It's not a debate, it's not an action that could be seen in a different manner. Maybe the referees need a bit of help with technology and the whole ground should see how long is left with a big clock," he said.
"Maybe that will be a debateable point, but to have a player two yards offside in the box is unacceptable. It's a decision that should've been given as an offside.
"It's a heart-breaking moment for us because we deserved the three points. The demands in this league are huge and the refereeing today was not up to the level, and that's very, very frustrating.
"Terry is already offside on the ball from Ivanovic's [original] ball, and Oscar's header makes him two yards more offside, so it's a major, major error. It's difficult to take.
"It's pointless [to talk to the referee], we've got other routes to speak with the chiefs of the organisation."