Mirallas' third goal in as many games against the Foxes and Lukaku's 10th this season gave Everton the win.
Goals by Kevin Mirallas and Romelu Lukaku kept champions Leicester firmly enmeshed in the relegation battle on Monday as they lost 2-0 to Everton in their Premier League clash.
Mirallas' third goal in as many games against the Foxes and Lukaku's 10th this season came against a Leicester side missing three key players, all of them suspended, including striker Jamie Vardy.
The only consolation for Leicester was that two of the bottom three Sunderland and Swansea lost but even so they are only three points above the relegation spots.
For Everton it was their first away win in three months.
Leicester made their point about Vardy's three match ban -- for a red card against Stoke last weekend -- by placing masks of the England striker on the 30,000 seats.
Vardy seated in the stands played along putting one on.
Both sides failed to fire in the first-half and the Everton fans had to wait till the 43rd minute before their side mustered their first effort on goal, albeit off target, with Ramiro Funes Mori heading over the crossbar.
Leicester manager Claudio Ranieri tried to change things at the break bringing on influential midfielder Danny Drinkwater -- who has just returned from being out injured with a knee problem -- in place of Shinji Okazaki as he pushed three men up front.
Initially the ploy seemed to be working with first Islam Slimani and then Demarai Gray going close with shots from outside the penalty area.
But one long clearance later and the Foxes were flattened.
Goalkeeper Joel Robles sent a huge clearance down the middle that saw Mirallas sprint goalside of Marcin Wasilewski and Wes Morgan.
Three touches later and the ball was in the back of the net courtesy of a deflection from Wasilewski that gave Kasper Schmeichel no hope of making the save.
Ranieri made a double change midway through the half and it almost paid immediate dividends.
Loud boos rang around the King Power Stadium when the lively Gray, arguably City's best performer, was replaced by Leonardo Ulloa with Riyad Mahrez also coming on for Andy King.
Within a minute of their arrival Ulloa should have nodded home from Danny Simpson's fine hanging diagonal ball but headed straight at Robles who caught under the crossbar.
There followed long periods of Leicester pressure with Everton very much having their backs to the wall.
But try as they might the home team failed to create a single noteworthy opportunity.
Everton should have wrapped things up when Lukaku squared for Idrissa Gueye who somehow ballooned his effort over an open goal from six yards.
Drinkwater was booked for an obvious push on Aaron Lennon as City's frustrations mounted.
In injury time and with Leicester pouring forward Ross Barkley lashed a clearance forward from the edge of his own box.
Lukaku shrugged aside Morgan's challenge, sprinted towards the box, coasted past Wasilewski and finished beyond Schmeichel.