Lazio kick-started their Champions League campaign with a last-gasp 2-1 win against Celtic as Pedro netted in the final seconds of Wednesday's clash in Glasgow.
Maurizio Sarri's side arrived at Parkhead under a cloud after a wretched run in Serie A.
But Lazio banished the gloom in the most dramatic fashion when Pedro headed home with just moments left to stun raucous Parkhead into silence.
Celtic took the lead through Japan striker Kyogo Furuhashi's first Champions League goal.
However, the Scottish champions' hopes of winning on home soil in the Champions League group stage for the first time in 10 years were dashed.
Matias Vecino headed Lazio's equaliser before the interval and former Chelsea winger Pedro produced the late plot twist.
"We had a great first half, then we had a period of being under pressure, but this time we showed more character to stay in the game. When that happens, usually you are rewarded," Sarri said.
"I told the lads before the match that we were nearly there, not to listen to what anyone else says.
"We are close to being competitive. I hope this result can give us a positive reaction, some confidence and belief."
Sarri's men are languishing in 16th place in Serie A and looked vulnerable for long periods in the east end of Glasgow.
But once again they bagged a priceless late goal in Europe's elite club competition after goalkeeper Ivan Provedel's stoppage-time equaliser in their opening group game against Atletico Madrid.
Following a defeat against AC Milan at the weekend, Sarri had criticised the state of his squad in the wake of what he deemed a poor transfer window.
This gritty display was hugely encouraging against that troubled backdrop, leaving Lazio second in Group E on the same points as leaders Atletico.
Celtic have not claimed three points from a Champions League home game since a 2-1 win over Ajax in 2013 and the wait will go on at least until they host Atletico on October 25.
Beaten at Feyenoord in their opening group game this season, Celtic have won just one of their last 23 Champions League group games and face an uphill task to qualify for the last 16.
- Sting in the tale -
"We're bitterly disappointed. It was a devastating way to lose because we deserved something, but we'll analyse it and learn the lessons," Celtic boss Brendan Rodgers said.
"To concede late on like we did, it's really harsh on us. But there is learning there, you have to secure the ball in the game and if you're not going to win it at that stage, you certainly can't lose it."
Revved up by the vociferous support of the sell-out crowd, it took just 12 minutes for Celtic to make the breakthrough with a flowing move.
Daizen Maeda stroked his pass to Matt O'Riley, who cushioned a first-time ball towards Kyogo.
Timing his run perfectly, Kyogo clipped a cool finish under Provedel from 10 yards to spark wild celebrations on the pitch and in the stands.
Sarri's men snatched an equaliser against the run of play to ease their coach's angst in the 29th minute.
It was a sloppy goal for Celtic to concede as they failed to clear a corner and Alessio Romagnoli headed down for Vecino to nod home from close range despite Joe Hart's attempt to claw the ball off the line.
Luis Palma thought he had won it in the 81st minute when he drilled home from Maeda's flick, but a VAR check ruled the Celtic substitute was offside.
There was a painful sting in the tale for Celtic as Lazio stole the points in the fifth minute of stoppage time.
Cameron Carter-Vickers lost possession and Matteo Guendouzi's perfectly weighted cross picked out Pedro, who rose highest to loop his header into the far corner from six yards.
