Branislav Ivanovic scored what could be a decisive goal as Chelsea held Paris St Germain to a 1-1 draw in Paris tonight.
The Londoners took the lead in The Champions League first leg knockout stage game when the Serbia defender reacted quickest to head home past goalkeeper Sirigu with 10 minutes of the first half to go.
But Chelsea were sluggish in the second half and the Paris side were level through Edison Cavani.
Chelsea we poor by their usual standards but a welcome result nevertheless.
Thiabaut Courtois thwarted Matuidi and Ibrahimovic on 10 minutes as PSG opened the Blues up on the left and both the home side players had headers on target. Courtois, restored to the starting line-up by Jose Mourinho at the expense of Petr Cech managed to party away both powerful efforts.
Diego Costa, back after a three-match suspension then his weight around with needless fouls on Thiago Silva and Ibrahimovic, which drew the attention of Turkish referee Cuneyt Cakir, who had words with the Brazil-born Spain striker.
Sirigu finally had something to do on 25 minutes when Eden Hazard drilled in a right-sided cross but the goalkeeper snuffed it out.
Edison Carvani forced Courtois into another near post save from a corner on 34 minutes as the home side teased the Chelsea full-backs into errors.
But with 10 minutes of the half remaining the Blues took the lead with their first attack in goal. The ball came in on the left from John Terry, was flicked on by Gary Cahill and up popped the Serbian defender to head the ball past Sirigu.
Ibrahimovic tried a dipping free-kick seconds before the break, but the ball sailed high over Courtois's goal.
There were no changes by either side at half-time.
Gregory Van der Wiel entered the ref's book, on 51 minutes for one too many fouls in Hazard as the home side showed increased aggression.
That aggression reaped dividends two minutes later when a simple left-wing cross by Matuidi was headed past Courtois by an unchallenged Cavani, as the levelled the score.
Quite what Cahill was doing, marking air, is anybodies guess.
PSG should have taken the lead on 60 minutes but saves by Courtois and a double touch by Chelsea players John Terry Cesar Azpilicueta stopped Ibrahimovic and Levezzi from scoring.
The pressure got to Ivanovic on 65 minutes as he hauled down Cavani, - a yellow card was inevitable.
From the resultant free kick David Luiz glanced a header towards goal, Courtois managed to tip the effort away for a corner.
Cesc Fabregas follows his team mate soon after as a sluggish Chelsea struggled to contain a lively PSG.
Juan Cuadrado made his Champions League bow, replacing Willian with 11 minutes to go as Jose Mourinho tried to mange the game.
But Chelsea almost came unstuck 60 seconds later as Cavani inched the ball wide of Courtois and thankfully, the goal too.
Costa was replaced by Loic Remy as the striker looked out of sorts for most of the game. He was quickly followed by Oscar, on for ineffectual Fabregas.
With seconds to go, Courtois made a sensational save from Ibrahimovic as the Sweden's striker' header seemed destined for the goal, before Courtois tipped the ball away from goal.
That was the last of the action. The return leg is at Stamford Bridge in three weeks time.
PSG: Sirigu, van der Wiel, Marquinhos, Thiago Silva, Maxwell, Verratti, Luiz, Matuidi, Lavezzi, Ibrahimovic, Cavani.
Subs: Douchez, Camara, Bahebeck, Digne, Rabiot, Pastore, Kimpembe.
Chelsea: Courtois, Ivanovic, Cahill, Terry, Azpilicueta, Ramires, Matic, Willian, Fabregas, Hazard, Costa.
Subs: Cech, Luis, Zouma, Oscar, Drogba, Remy, Cuadrado.
Referee: Cuneyt Cakir (Turkey)