John Obi Mikel scored his sixth goal in 10 seasons with Chelsea but the Blues face a first leg deficit against Paris Saint-Germain as his strike was sandwiched by Zlatan Ibrahimovic and Edinson Cavani.
The Swede opened the scoring with a free kick that deflected off the Nigerian before the midfielder levelled the scores when he turned home Willian's corner.
But Cavani beat the offside trap with time running out to give the French side the advantage.
PSG made a much stronger start and penned Chelsea back into their own half as the Blues failed to retain possession.
Zlatan Ibrahimovic gave the visitors a scare with a 35-yard free kick after 10 minutes that whistled over Thibaut Courtois' crossbar.
The French side were passing the ball around for fun and forced the visitors into playing a compact back four in order to resist the threat.
Indeed, Chelsea's main threat was coming from the counter attack with Pedro causing problems down the right flank when he got the ball.
The Blues started to gain a foothold in the contest after 20 minutes as they started to string a few passes together and make the Ligue 1 champions elect do some defensive work.
And Diego Costa was desperately unlucky not to open the scoring, giving Chelsea a critical away gold, when his header from Baba Rahman's cross was brilliantly deflected onto the bar by Kevin Trapp's fingertips.
Paris were still dangerous and Ibrahimovic escaped the clutches of Gary Cahill but could not get his header off target.
Lucas Moura was a persistent thorn in Chelsea's side and holding John Obi Mikel was booked for bringing him down at the edge of the penalty area seven minutes before the break.
And from the free kick, Ibrahimovic's strike was deflected off the booked Nigerian, who was turning his back, and beat Courtois, who had dived to his right.
But Mikel made amends on the stroke of half-time as he turned home Willian's corner for his first goal since scoring against Sporting Lisbon in December 2014 and only the sixth time he's found the net in his long association with the Stamford Bridge club.
Chelsea were lifted by the away goal and nearly had another from a counter attack but Costa was, once again, denied by Trapp after a delightful through ball from Willian.
PSG were still dangerous and Angel Di Maria forced a good save from Courtois to highlight the threat.
The Belgian was needed again to deny Lucas as the Brazilian broke through the Chelsea defence.
It was backs to the wall stuff from Chelsea and Blaise Matuidi saw his effort blocked by the combined dedication of Ivanovic and Gary Cahill.
Oscar replaced the ineffective Eden Hazard and nearly gave the Blues the lead but Trapp was quickly off his line to deny the Brazilian.
PSG substitute Edinson Cavani, though, made the bigger impact as he latched onto a ball over the top to slot the ball under Courtois after beating the offside trap.
All is not lost for Chelsea though as a 1-0 win will see them progress on the away goals rule.
