Ruben Loftus-Cheek came off the bench and signalled his intent for more starts with a smart goal that sealed a confident 2-0 victory for the blues against Scunthorpe United T the Bridge in the FA Cup.
Guus Hiddink opted to keep the kids waiting in the nursery as the big boys donned the shirts and sock and ran onto the Stamford Bridge turf, but the 19-year-old waited for his chance and struck on 68 minutes to show former manager Jose Mourinho that he was worth persevering with.
With a sop to he upcoming match on Wednesday with WBA at home, Hiddink rested Thibaut Courtois and John Terry to the bench. In came Asmir Begovic and Gary Cahill - hardly risk appointment.
The decision proved to be correct as the Blues took just 13 minutes before taking the lead against the League One side.
A regulation right-wing cross by Ivanovic, was tucked home, inadvertently by Jordan Clarke, although Diego Costa was on the spot and muddied the waters. However the striker failed to celebrate.
Either way the struggling Premier League side took the deserved lead.
A blaster from Cesc Fabregas and another by Pedro brought excellent saves from Luke Daniels in the Iron's goal.
The visitors's first direct effort on goal, came on 34 minutes, from the boot of Luke Williams, but Begovic was equal to the task, smothering the curling, right-footer easily.
At halftime, Hiddink brought on Ruben Loftus-Cheek for Oscar.
But it was the the Iron who should have scored eight minutes into the restart when Ramires upended Kevin Van Veen just inside the Chelsea penalty area. Bizarrely, referee Craig Pawson waved away the credible demands from the Scunthorpe players.
As is always the case in these circumstances, the injustice is compounded by conceding another goal. And it duly came from the cultured left boot of Loftus-Cheek, who, after excellent set up play by Willian and Cesar Azpilicueta coolly slotted home from seven yards out past Daniels on 68 minutes.
It was the 19-year-old's first goal for the club.
Kenedy was soon on for Pedro as Hiddink chose to rest key players for Wednesday's league clash against WBA.
Jordan Clarke smashed a wonderful shot against Begovic's angle of crossbar and post with three minutes on the clock but in truth a mediocre Chelsea performance was still far too good for the League Two outfit and the Blues go into Monday evening's draw for the fourth round without having to raise too much of a sweat.
Teams: Chelsea, Begovic, Ivanovic, Fabregas, Zouma, Ramires, Oscar, Pedro, Costa, Willian, Cahill, Azpilicueta
Subs Courtois, Baba,Mikel, Traore, Kenedy, Terry, Loftus-Cheek
Scunthorpe Utd: Daniels, Laird, Mirfin, Madden, Van Veen, Bishop, Dawson, Wallace, Ness, Clarke
Subs: Anyon, ,Wiseman, McAllister, Canavan, Adelakun, King, Wootton
Referee: Craig Pawson