Chelsea stuttered into the Conference League semi-finals despite suffering a deserved 2-1 home defeat to Legia Warsaw on Wednesday night.
The Blues relied heavily on their 3-0 first-leg advantage to secure a 4-2 aggregate victory at Stamford Bridge.
Enzo Maresca's side produced an insipid display that did little to enthuse fans already feeling disenchanted after the weekend's limp 2-2 draw with Ipswich.
There were audible boos from the home crowd at full time.
Steve Kapuadi restored Legia's lead eight minutes into the second half
Reuters
Legia Warsaw stunned Chelsea early when Filip Jorgensen brought down Tomas Pekhart in the box after just 10 minutes.
Pekhart converted the resulting penalty, though Jorgensen got both hands to the modest spot-kick but failed to keep it out.
Chelsea equalised in the 33rd minute when Jadon Sancho, a bright spark for the hosts, teased his man on the right before delivering a cross that Marc Cucurella swept in.
Steve Kapuadi restored Legia's lead eight minutes into the second half, heading home following a poorly-defended corner.
The Blues looked mediocre throughout, with a much-changed side struggling to impose themselves on the match.
Chelsea held 70% possession but failed to capitalise on their dominance, with the visitors finding it far too easy to break through their defensive line.
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Jorgensen, Josh Acheampong and Tosin Adarabioyo were particularly frail at the back, something that may concern Maresca going forward.
The hosts had two goals ruled out for offside, including a second from Cucurella before the break and a bundled effort from Tyrique George.
Chelsea took 16 shots throughout the match compared to Legia's 13, with eight on target to the visitors' five.
The Blues forced the opposition keeper into six saves but were ultimately unable to find a second goal.
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Legia Warsaw fans brought the noise but Chelsea fans booed the players off
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At the other end, Legia Warsaw missed several glorious opportunities to further close the gap.
Maxi Oyedele was particularly impressive for the visitors, making four tackles, four clearances and two interceptions while winning four duels.
The midfielder also made five progressive passes into the final third.
Chelsea's progression to the semi-finals comes despite a performance that left them looking anything but Champions League material in waiting.
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The Blues toiled to their aggregate victory on a humbling night at Stamford Bridge.
While never seriously in danger of failing to reach the last four of this year's Conference League, their lacklustre display will do little to boost confidence.
Chelsea will now turn attention to Premier League fixtures against Everton and Fulham as they continue their push for a Champions League spot.
