Chelsea set up a FA Cup quarter-final tie against Manchester United with a 2-0 win against Middlesbrough at the Riverside Stadium.
The hosts managed to hold off Rafael Benitez's men until half-time but could do nothing about Ramires' deflected effort which gave the visitors the lead on the hour mark on Wednesday.
Victor Moses made sure of Chelsea's progress with his sixth goal of the season midway through the second half.
A packed Riverside Stadium saw the hosts get off to a shaky start as Chelsea wasted several early chances.
Paulo Ferreira was inches away from getting on the end of a cross from Oscar at the far post before Fernando Torres fizzed another fine pass across the Boro area with no team-mate there to meet it.
The hosts survived another scare soon after when Moses picked out Oscar in the box, but the Brazilian's first-time effort was well blocked by Jason Steele.
Scott McDonald wasted a glorious chance for Boro when he headed inches wide after
meeting Nicky Bailey's cross in the 26th minute.
Boro continued to grow into the game and almost had a chance when Petr Cech spilled Mustapha Carayol's long-range shot five minutes before the break, but John Terry reacted first and was on hand to clear the danger.
Benitez would have had some stern words for his players at the break after they allowed Boro back into the game.
Chelsea came out in the second half with intent and were rewarded just six minutes after the break.
Ramires curled home a right-footed shot from the edge of the area which took a deflection off Torres on its way into the top corner.
The visitors could have doubled their lead on the hour but Torres' shot whistled over the bar after he managed to beat Boro's offside trap.
The game was eventually wrapped up in the 72nd minute when Oscar and substitute Eden Hazard picked apart the Boro defence before Moses capped off a fine move with an easy tap in.
Hazard had transformed the game after coming on in the 58th minute
Oscar wasted a chance to get Chelsea's third and Middlesbrough came close through Seb Hines in the closing stages.
Another chance went begging for Boro when Ishmael Miller sliced his left-footed shot into the side netting at the death but at that point the visitors' progress into the last eight was already secure.