Half-time: Chelsea 0 Swansea 1
A defensive aberration seven minutes before the break gifted Swansea the lead in the Capital One Cup semi-final first leg.
Chelsea had dominated at Stamford Bridge before Michu opening the scoring against the run of play.
Branislav Ivanovic hesitated after collecting a routine pass from keeper Ross Turnbull near the edge of the penalty area and was robbed by Jonathan de Guzman.
The ball then ran to Michu, who gleefully fired home his 16th goal of the season.
By that stage Chelsea should have been at least a couple of goals in front.
Juan Mata had missed their best chance, meekly side-footing straight at keeper Gerhard Tremmel after being found unmarked by Eden Hazard.
Tremmel also kept out a toe-poked effort from Ramires following great link-up play involving Hazard and Oscar.
Gary Cahill headed over as Chelsea continued to have the upper hand, before Cesar Azpilicueta shot wide after dispossessing Swansea’s Wayne Routledge.
It seemed only a matter of time before Chelsea broke the deadlock, yet it was City who struck first.
The home fans repeatedly chanted the name of Frank Lampard, with doubt continuing to surround the popular midfielder’s future as he approaches the end of his contract.
Some of the Blues faithful vented their frustration by booing club chairman Bruce Buck during a pre-match presentation on the pitch.
Lampard was named among the substitutes along with recent signing Demba Ba, while Fernando Torres returned to the starting line-up.
Chelsea: Turnbull, Azpilicueta, Ivanovic, Cahill, Cole, Luiz, Ramires, Hazard, Oscar, Mata, Torres.
Subs: Hilario, Lampard, Ferreira, Marin, Ba, Bertrand, Ake.
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