Graham Potter began life at Chelsea with a 1-1 draw with Salzburg in the Champions League group stages.
The Blues displayed a formidable intensity and structure in their first game under their new boss but were undone by a late Salzburg sucker-punch at Stamford Bridge.
After a pre-match period of remembrance for the late Queen Elizabeth II, Chelsea came flying out of the traps and their first half-chances of the evening came through Kai Havertz and Pierre-Emerick Aubamayeng, but neither could keep their successive shots from the edge of the area on target.
Havertz then had a goal-bound header blocked by Benjamin Sesko as Potter's men continued to play at a high intensity in the opening stages.
A through ball from Raheem Sterling came so close to being converted by Aubameyang, only for Strahinja Pavlovic to make a last-ditch challenge to deny the striker.
After a stoppage to fix the referee's communication system, Mason Mount lashed a fierce strike just wide of the post as the Blues upped the ante again.
At the other end, Sesko came close to putting Salzburg ahead after a neat swivel and snap-shot, but Kepa Arrizabalaga made a stretching save to deny him.
Chelsea wanted a penalty in first-half stoppage time when Mateo Kovacic's header hit Bernardo's hand, but the referee stood firm and waved play on.
Just after the break, Sterling broke the deadlock to become the first goalscorer of the Potter era. Mount's low cross managed to evade everyone, allowing Sterling to ghost in, set himself and pick out the far corner of Philipp Kohn's net.
Salzburg seldom created much but came close to equalising when Noah Okafor found space for a free header, but his glanced effort was held by Arrizabalaga.
But Okafor didn't make a mistake minutes later when he notched in Salzburg's leveller. Thiago Silva failed to deal with Chukwubuike Adamu, who ghosted past his slide tackle and squared for Okafor to tap in.
Reece James fired over at the end of a clever free-kick routine almost immediately from kick-off as Chelsea looked to restore their lead.
Hakim Ziyech was denied by Kohn from close range after he met a Sterling cross, and Armando Broja's vicious half-volley sailed over in stoppage time as the Blues had to settle for a point.
Chelsea player ratings
GK: Kepa Arrizabalaga - 6/10 - Provided an option to play from the back. Made a decent sprawling save but was largely untroubled.
CB: Cesar Azpilicueta - 5/10 - Looked every bit his 33 years of age at times. Beaten by the run of Okafor for the equaliser.
CB: Thiago Silva - 6/10 - Put in a series of excellent tackles and interceptions, but was too weak in his challenge leading to Salzburg's equaliser.
CB: Marc Cucurella - 6/10 - Flittered between centre-back and left-back. Saw a lot of the ball but wasn't as creative he could be.
RM: Reece James - 5/10 - Pushed up high as a wing-back at times in Potter's fluid system. Couldn't quite bring all the facets of his expansive game together.
CM: Mason Mount - 7/10 - Dropped very deep to track back, collect the ball and build attacks. Provided the assist for the opening goal.
CM: Jorginho - 5/10 - Pressed into a few errors early on and struggled to keep up with the high tempo of the game but eventually settled into the rhythm.
CM: Mateo Kovacic - 5/10 - Showed his obvious quality in flashes but not throughout the entire match.
LM: Raheem Sterling - 8/10 - Played as a wing-back at times (the Leandro Trossard role, if you will), but that meant he had lots of room to run into. Took his goal excellently.
AM: Kai Havertz - 6/10 - Pressed and created plenty of havoc in the first half. Was a bit more toothless in the second and was duly hooked.
CF: Pierre-Emerick Aubameyang - 5/10 - Got himself into good areas and led the line fairly well, but couldn't find the net on his home debut.
Manager: Graham Potter - 6/10 - Chelsea looked like a team who had been coached by a manager for much longer than six days, testament to Potter and his backroom staff. However, their issue in creating clear cut chances and converting them remain.
SUB: Ruben Loftus-Cheek (66' for Havertz) - 5/10
SUB: Armando Broja (66' for Aubameyang) - 5/10
SUB: Conor Gallagher (81' for Kovacic) - N/A
SUB: Hakim Ziyech (81' for Azpilicueta) - N/A
SUB: Christian Pulisic (84' for Sterling) - N/A