Nigerian John Obi Mikel scored a precious away goal but Edinson Cavani came off the bench to give Paris St-Germain the advantage after the first leg of their Champions League last-16 tie against Chelsea.
The hosts went ahead through Zlatan Ibrahimovic’s deflected free-kick.
Mikel capitalised on some terrible defending to sweep home a deserved leveller from six yards.
Chelsea’s stoic defending had them on course for a draw, before Cavani steered home Angel di Maria’s pass.
The 29-year-old Uruguay striker, who has been used primarily as back-up to Ibrahimovic this season, scored moments after substitute Oscar spurned a chance for the visitors.
But with the second leg to come at Stamford Bridge on 9 March, the Blues are still very much in contention thanks to Mikel’s goal – and Thibaut Courtois’ late save from Ibrahimovic.
Some have called this a make-or-break week for Chelsea, with this match followed by an FA Cup tie against Manchester City on Sunday.
With their Premier League title defence already over, Guus Hiddink’s men will know by the end of the weekend whether they can salvage anything from a disappointing domestic season.
But whatever happens against City, they will be hopeful of progressing in the Champions League after a promising performance in the French capital.
This is the third successive season these teams have been drawn against each other, and both previous ties were decided on away goals. Chelsea progressed in 2014 despite losing the first leg 3-1 in Parc des Princes – though admittedly they were a more formidable outfit than this vintage – but were beaten last season.
This was Chelsea’s first defeat since Hiddink took charge after Jose Mourinho’s sacking in November, leading his team to a 12-match unbeaten run.
The Blues thumped Newcastle 5-1 at the weekend, but Laurent Blanc’s men were a step up in class.
The Ligue 1 leaders are unbeaten in 44 league games and lead second-placed Monaco by 24 points, though before the match Hiddink questioned the quality of the French top flight.
There is no doubting the quality of players at PSG’s disposal, however, with Blanc able to recall the likes of Ibrahimovic, Marco Verratti and Lucas Moura after resting them at the weekend.
The hosts were by far the superior side in the opening 17 minutes, enjoying 74% of possession, but all they had to show for it was a long-range Lucas strike.
As the visitors dragged themselves back into the match, Ibrahimovic scored against the run of play. Indeed, were it not for Kevin Trapp’s fingertips diverting Diego Costa’s header onto the crossbar, the Blues would have been ahead before the Swede scored his first goal against them.
Ibrahimovic’s free-kick struck Mikel en route to beating Courtois, but the Nigeria midfielder quickly made amends by capitalising on poor PSG defending from a corner.
With John Terry and Kurt Zouma injured, Chelsea were without their first-choice centre-backs.
But the makeshift partnership of Gary Cahill – who blocked bravely from Blaise Matuidi – and Branislav Ivanovic withstood wave after wave of second-half PSG attacks until they were eventually breached in the closing stages.
They were ably supported by Courtois, who made a series of saves, though he was culpable for allowing Cavani to thread the ball between his legs and in at the near post.
Terry’s hamstring injury resulted in a promotion for Ghana defender Baba Rahman, and the left-back played his part in the Blues’ rearguard display.
