MAURICIO POCHETTINO’S hobbling heroes helped Chelsea take a cautious step towards Wembley in his first season as boss.
Benoit Bediashile put them ahead in his first appearance of the season following a frustrating hamstring injury.
And skipper Reece James made his first start since the opening game of the campaign thanks to a similarly dicky leg and added much-needed steel to the soft-touch Blues.
It was a long way from a classic Chelsea steamrollering of yesteryear - even against lower league opposition.
But Pochettino still finds himself in the quarter finals of a major tournament just four months after taking over the reins as head coach.
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As with most things at this transitional club right now, the one goal lead looked fragile until old soldier Raheem Sterling curled in a peach of a second bang on the hour to seal the win.
This young squad is still feeble in the very frontline with striker Nicolas Jackson gradually fading from the game after a promising start.
Having been urged to wake up by a heckler at the weekend, the Senegalese forward had two shots on goal inside the first ten minutes but was unable to add to his three goals this season.
And despite enjoying superiority in almost every department, it took a misjudgement by Rovers’ keeper Leo Wahlstedt to hand Chelsea the lead on half hour.
Conor Gallagher clipped a cross into the six yard box from a short corner and Wahlstedt managed only to paw at the ball instead of land a decisive punch into clear space.
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It was a gift to advancing Chelsea defender Badiashile who stepped up and lamped a shot into the back of the net from among a crowd of defenders.
Pochettino made four changes to his team that was sunk 2-0 at home by Brentford at the weekend as his battle to construct a sense of consistency took a backward lurch.
With James hopefully back long term now there is a definite feel of added physicality and pace to Chelsea.
The captain reminded everyone of his speed by latching onto a ball from Enzo Fernandes and lashing a shot straight at keeper Wahlstedt.
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In the 24th minute he let rip with a precise diagonal shot across goal that fired narrowly wide.
Blackburn love the freedom of a cup tie and scored 17 goals in previous rounds of this competition prior to kick off. One of those was an 8-0 stuffing of League Two Harrogate.
Yet Rovers are a patchy mid-table Championship side and luckily for chelsea the visitors brought their league form with them to West London.
Two minutes into the second half, young forward Harry Leonard was put clean through but outstripping the Chelsea defence for pace sent his shot well wide and fluffed his big chance on the big stage.
Even so, Rovers can regard themselves desperately unlucky not to have been awarded a penalty in the first half when Blues’ midfielder Conor Gallagher handled a cross hit at pace by Callum Brittain.
Gallagher’s back was turned but his left hand was certainly flapping in an unnatural position. The absence of VAR made for a more flowing game but at cost to Rovers.
Likewise, Chelsea could lay claim to a spot kick in the first half when Raheem Sterling appeared to be felled by Rovers skipper Lewis Travis in the 10th minute.
Sterling’s classy goal was the trigger for Pochettino to take James off with a good hour under his belt but with Monday’s visit to Tottenham very much in mind.
