Goals from Michu and Danny Graham gave Swansea a shock 2-0 League Cup first leg lead from their away tie at Chelsea.
Blues' defender Branislav Ivanovic was at fault for both goals which came at the end of each half of the game at Stamford Bridge and the Swans now have two away goals for the home leg at the Liberty Stadium in a fortnight.
Chelsea went close on 11 minutes when good build up play involving Eden Hazard and Oscar created an opportunity for Ramires but he could only toe-poke his shot at Gerhard Tremmel from inside the area.
Michu had Swansea's first strike on goal from distance on 21 minutes but it was fairly comfortable for Ross Turnbull.
Juan Mata then side-footed straight at Tremmel when in a good position on 26 minutes, before he fired just past the far post following a clever flick from Oscar just after the half-hour.
Chelsea were made to pay for their profligacy on 39 minutes when Ivanovic was caught in possession by Jonathan de Guzman and he played in Michu to coolly convert his 16th goal of the season.
Ivanovic almost made amends two minutes before the interval but his effort was parried away by Tremmel.
Chelsea struggled to find a way through a stubborn Swans' backline in the second half with David Luiz going close with a low strike from the edge of the area which Tremmel got down well to save on the line on 58 minutes.
Frank Lampard tested Tremmel from outside the area and Demba Ba failed to hit the target with two late headers.
However, Ivanovic pressed the self-destruct button in stoppage time with a back-pass straight into the path of Graham who went round Turnbull and fired into the empty net to put the Swans' a step closer to Wembley.