The Europa League's top scorer Olivier Giroud took his tally to 10 with his strike against Slavia Prague
Chelsea held off a second-half comeback by Slavia Prague to progress to the Europa League semi-finals with victory in the second leg at Stamford Bridge.
Maurizio Sarri's side were cruising at half-time with a four-goal aggregate lead before Petr Sevcik produced two sensational strikes as the nerves crept into a previously dominant Chelsea performance.
Buoyed by their noisy supporters, the visitors pushed forward as they tried to force a way back into the game but time defeated them as the Blues regained their composure to close out victory.
Having secured a valuable 1-0 advantage in the Czech Republic, Chelsea raced into a three-goal lead in west London courtesy of goals from Pedro, Olivier Giroud and a calamitous Simon Deli own goal.
Slavia captain Tomas Soucek headed in his side's first goal before Pedro doubled his tally just 63 seconds later.
Chelsea travel to Germany for the first leg of their last-four tie with Eintracht Frankfurt on Thursday, 2 May.
Chelsea produce two contrasting halves
Chelsea lost ground in the race for the top four in the Premier League with defeat at Liverpool on Sunday, but as Sarri indicated before kick-off, the Blues were solely focused on the job in hand during the opening period against Slavia.
They were dominant from the first whistle, exploiting the visitors with clinical accuracy and scoring four first-half goals from four shots on target.
They took a third-minute lead with a fluid move down the right involving Cesar Azpilicueta before Pedro played a neat one-two with Giroud to streak clear and lift the ball over goalkeeper Ondrej Kolar.
It was 2-0 moments later when Pedro struck the post after Eden Hazard flashed the ball across the face of goal, only for Deli to helplessly divert the rebound over his own line from close range.
Giroud rolled in his 10th goal of this season's competition to extend the lead before Soucek pulled one back, but Pedro's second restored a three-goal lead on the night.
Sarri's side lost their rhythm after the break and only mustered two shots at goal as Slavia stepped up their intensity. Sevcik unleashed two similar strikes with his potent left foot, beating Kepa Arrizabalaga first at his near post before then finding the top corner with a stunning effort five minutes later.
Chelsea's mini-capitulation had echoes of their display at Anfield on Sunday - when two goals in eight minutes at the start of the second period settled the match - but the Blues had useful cushion to protect them on this occasion.
Victory ensured Chelsea became the first English club to win 11 matches in European competition in a single season, but Sarri must help his players to find consistent displays for the whole game if they are to deliver a first European trophy since 2013 - and with it Champions League football next season.
Slavia salvage their pride after the break
With 45 minutes played, Slavia were staring at a humiliating defeat by a confident Chelsea attack, but they will be encouraged by their second-half performance as they chase the Czech league title.
Jindrich Trpisovsky's side are five points clear with two games to play in their domestic league, and they are clearly capable of competing against some of Europe's big hitters.
Slavia posed a threat from set-plays as Deli almost scored their first goal with a powerful header before Soucek opened their account.
Chelsea struggled with their aerial power and physicality as the visitors produced more shots over 90 minutes than the hosts.
Man of the match - Pedro (Chelsea)Chelsea forward Pedro had a hand in three of Chelsea's four goals - scoring two and assisting another
More to follow.
