Chelsea face an uphill battle in their quest for a Champions League quarter-final place after losing 3-1 in Napoli tonight.
Ezequiel Lavezzi notched a brace while Edinson Cavani also netted to put the Italian side in command after the first leg of the last-16 tie.
It was Chelsea who took the lead, as Juan Mata capitalised on a defensive error from Paolo Cannavaro to score from eight yards.
David Luiz came within inches of doubling the Blues' advantage but headed just wide from Mata's corner.
Napoli then turned the game around with two goals in the closing stages of the first period.
The equaliser came through Lavezzi, who combined with Cavani before sending a curling effort past Petr Cech from 25 yards.
Having provided the first, Cavani added his name to the scoresheet when he nodded in from close range to put Napoli ahead in first-half stoppage time.
A mistake from Luiz then allowed Cavani in once more. The Uruguayan squared for Lavezzi to finish from inside 12 yards on 65 minutes.
Matters could have been worse for Chelsea as Ashley Cole cleared off the line from Christian Maggio in the closing minutes.
In an end-to-end game, Didier Drogba had a golden opportunity to reduce the deficit but sent his injury-time volley off target.
The return leg takes place at Stamford Bridge on March 13.
