"He scores when he wants," screamed 5,000 Chelsea fans as Mikel's bullet header propelled Chelsea into the 4th round of the FA Cup.
The Blues defeated Derby County 2-0 at Pride Park, the second goal coming from Oscar six minutes after Mikel's, on 71 minutes..
The Nigeria midfielder, celebrating his 300th appearance for Chelsea, rose to meet a deep Willian free-kick. The ball was expertly glanced on with a minimum loss of speed and the ball arrowed past luckless goalkeeper Lee Grant.
That was Mikel's fourth goal in a Blue shirt, bizarrely his third in the FA Cup. Six minutes later and the match was won and a visit from Stoke City awaits the west Londoners in the 4th round.
Midfielder Oscar unleashed a venomous right-footer from just inside the right apex of the Derby penalty area, that Grant hand little chance to stop.
It was game over at that point and Chelsea cruised to the end in third gear.
Derby made a fist of the game whenever that had a sustained period of pressure. But stand-in goalkeeper Mark Schwarzer was on hand to continue his record of playing twice for the Blues since his summer signing from Fulham and not conceding a goal.
An early mazy run by Oscar set the tone for the opening exchanges with Chelsea fully on the front footy, hoping to create a decisive break.
A somewhat optimistic chip, by Ramires on three minutes from the edge of the Derby penalty area almost caught Lee Grant napping, but then ball inched over his crossbar.
Derby, for their part, after surviving an opening salvo of attack, got to grips with the hectic pace of the game and started to create some passing moves of their own.
A lovely whipped in ball on 12 minutes from the left by Craig Forsyth was set up for Jaime Ward to tuck home, but Gary Cahill stuck out his left and intercepted beautifully from six-yards out to clear Derby's first worthwhile attack on the visitors' goal.
The Blues, having failed to make the early breakthrough went into their shells for 10-minute spell allowing Derby an increasing level of pressure.
A snap shot by Forsyth went over Mark Schwarzer's goal on 20 minutes.
A minute lat and Chelsea should have taken the lead. Samuel Eto'o failed to force Grant into a save when the Cameroon striker was sent clear by Mikel. He raced into the Derby area, but before getting a shot off, allowed Jake Buxton to intercept and clear.
Ward, then took the ball off Cole on the right before sending in a cunning curling right-footer almost from the byline. Thankfully for the Blues, Cahill got a nick on the ball sending it into the gleeful path of Schwarzer who smothered the ball - much to the relief of the 5,000 travelling Chelsea fans behind his goal.
Cahill was alive, on 28 minutes to the charge of fleet-footed Ward, who found himself free to race into the Chelsea area. The England centre-back was too big a target for Ward's shot which was deflected away for a corner.
Seconds later and the ball was up the other end, this time Ramires saw his 20-yard daisy-cutter inch wide.
Oscar came even closer a minute later when his curling, right-footed free-kick just eluded Grant's right post.
Oscar, almost opened the score, eight minutes before the break, when, after patient play by Willian, the ball was passed to Oscar. He decided the straight line route was appropriate and raced 20 yards forwards before unleashing a powerful drive that swerved and moved in the air, before arching just over Grant's crossbar.
Oscar tried his luck again, this time from 25-yards out, but again the same result, only the fans behind Grant's goal were troubled.
Cesar Azpilicutea at least forced Grant into making a save, but the Spain right-back's strike from the byline saw Grant dive low to his left and parry the ball away from danger. On the stroke of half-time, Ramires had a shot, it took a deflection before zipping off Grant's right post and went for a corner.
There were no changes from either manager at half-time.
Buxton made another fine clearance, this time from Willian as the Blues started the second period as they did the first in the attacking ascendancy.
But while it was still 0-0, anything could happen and Ward almost squeezed a goal for the home side on 53 minutes, but his left footer, took a deflection off Luiz and the sting as taken out of the shot. Schwarzer had time to change position and smother the effort which was arrowing into his left-hand corner.
Jose Mourinho decided that enough was enough and more energy was needed in the middle of the park, so he replaced captain Michael Essien with Eden Hazard, Mikel assumed the armband.
Fernando Torres was next to come in off the bench, this time replacing ineffectual Eto'o on 64 minutes.
One minute later and the Blues took the lead. Hazard had just being hacked down, wide on the left. Willian took a fine, deep curling free-kick and Mikel rose first to plant a fine header high and wide of Grant.
It was Mikel's fourth goal for the Blues, his third in the FA Cup.
Ramires was then booked for diving in the Derby penalty area by referee Andre Marriner.
Six minutes later and the tie was effectively over. Willian took a throw-in on the right. He fed Hazard who passed the ball onto Oscar. the Brazil midfielder took one touch before smashing a fierce right footer from just inside the Derby penalty area. such was the ferocity of the shot, that despite swerving in the air as well, Grant was unable to get to it and it crashed into the back of his net.
Torres then had two quick chances to cement the lead with 13 minutes to go. The first, arguable the easiest was when he latched onto a Willian through ball, cut inside, rounded Buxton before, losing his footing and sense and miskicking the ball, falling over in the process. With that embarrassment over, his second effort was at least on target and Grant did well to parry away his shot.
Schwarzer was forced into a smart diving save to his near post, with six minutes on the clock.
Youngster Lewis Baker, replaced Oscar with two minutes to go, marking the debut for the 18-year-old midfielder.
It's back to the league next Saturday for the tricky lunchtime encounter with Hull City.
Team: Derby County, Grant, Forsyth, Hendricks, Martin, Ward, Eustace, Hughes, Buxton, Dawkins, Wisdom, Keane
Subs, Legzdinis, Freeman, Sammon, Bennett, Whitebread, Bailey, Cisse
Chelsea: Schwarzer Cole, Luiz Essien, Ramires, Oscar, Mikel, Willian, Cahill, Azpilicueta, Eto'o
Subs, Cech, Torres, Mata, Hazard, Terry, Kalas, Lewis Baker
Referee: Andre Marriner