Sevilla looked set to suffer heartbreak on Thursday as they entered stoppage time in the second leg of their last-four tie against Valencia trailing 3-0 on the night and 3-2 on aggregate.
However, M'Bia then rose to head home a crucial away goal at the Mestalla and send Unai Emery's men through to a final against Benfica.
Rakitic found it difficult to comprehend what happened in the closing minutes and expects M'Bia's goal to go down in club history.
"None of us have words to explain what happened," the Croatian midfielder told AS. "We work so hard every day and we deserve it, and so do the fans.
"I'd be lying if I said I didn't think we were out of the final at 3-0. We tried to get there.
"M'Bia's goal was impressive. There should be a monument to it forever."
Sevilla won the UEFA Cup in 2006 and 2007, but Rakitic - who arrived from Schalke in 2011 - will be chasing his first silverware with the Spanish club when they face Benfica on May 14.
"I don't know what to say about Benfica," he added. "I just want to enjoy this game.
"When we get there (though), we want to win it."
